As a mechanic, ive sat in auto dealerships waiting to pick up a part at the parts dept and listened to the service desk presenting lists of "repairs" to poor unsuspecting souls..hearing the diagnosis and the parts and labor pricing is almost painful at times becuz i know what the real time involved for the work done should be and i know what the parts pricing should roughly be... its so sad... people are being fleeced alive, especially old people and women....these shops take full advantage of people ignorance and their helplessness to to their own repairs....integrity and ethics are often absent in this field.
it comes from being continuously in contact with humans that know ZERO about how cars work, the frequent " my car won't start , I think the starter is bad..." mechanic finds it was a burnt fuse, being honest will put maybe $ 20-30 bucks in his pocket, or letting the customer believe he was right, And charging him for the new starter,( which goes straight into his pocket cuz the old one works great and is already installed) ,and the imaginary 3 hours of shop rate in labor to install the imaginary starter, the customer's happy to pay it, and $30 for honesty , vs. $400 -600 for nothing........ they get used to easy money, and in time burn anyone and everyone... I think all mechanics should have three random repairs every 5 years, that are actually employees of the BAR, who bring in cars with issues , pre determined, and report on the mechanics, ability, how he went about diagnosing cause of issue, did more charges than needed appear on the bill, did any of the loose 1 & 5 dollar bills stuffed in the cupholder disappear, or the gold chain half hidden by drivers floor mat? I just got ripped off by a mechanic who quoted 3 estimates...$500 to get it to run better, $800 to be able to get on the freeway, and $1200 for everything to work right...one mechanic didn't clue in his partner what I was quoted, and when I brought the car in the next day ( having no other option)only the partner was there, I had to ask him , if there wasn't usually something I signed , that had a price and what needed to be repaired? He then asked me what the other guy quoted me....& hastily wrote $500 when he saw the look on my face....I came back to my car having the same exact issues, returning to them, then he told me the ECU needed to be replaced...and he had already ordered it, but wouldn't arrive for 2 days....so I went and got the exact same ECU and brought it to him ,but he now couldn't program it , and sente to his locksmith buddy who did it in 5 minutes, and charged me $300....I did a throte relearn, and the car ran exactly the same...same issues, no change... $500 for vague wiring repairs $65 for diagnostic/engine trouble code printout, which told him the same that I did when I brought the car, $140 for tested used ECU, and $300 to program it......$1000 later, and I'm the same exact place I was before... I'm going to his shop tomorrow, and I'm so pissed off, I can barely see straight...my Nissan buddy finally gets back to me, so I ask him why would mechanic tell me he found the problem, make the repair, release the car to me only after payment, the problem not be fixed and then state he found the real cause of the problem... "To take your money" , my buddy says...... what do I do next?
Does California Automotive Repair Act , permit a customer blatantly ripped off, to pummel the crooked mechanic until he agrees to fix it right, and right now?
I cannot remember how many times I have paid for parts that were not broken. Sir you are a breath of fresh air. Finally I find a mechanic who does not shotgun a problem with parts until the problem goes away.
Many thanks my friend. Indeed buying parts should be the result of the diagnosis, not the method of it. But it takes knowledge of systems to do the diagnosis and I appreciate the few people like you who are willing to dedicate time and effort to that. In fact it is exactly why I made this channel.
I absolutely love your shop policy, more shops need to implement this policy: If you are unable to fix the problem, the parts come out of your pocket. There are too many mechanics out there who just throw parts at a car and pray that it fixes the problem. Good to see techs out there who value the customer's time and money.
@Matt, all of those issues I have been having with my 01 S-10 4.3L were because of a clogged pre-cat, and it blew out the back half of it into the primary cat. Recently, the vehicle would hardly get out of its own way, and on the road it wouldn't accelerate for $hit!! Other than the obvious symptoms, I used an infrared temp gun, and the temp at the back of the pre-cat was 150* lower. The engine was bucking, fuel trims were very lean, was throwing a P0101 code, P0300/P0304 code(s), burning excessive fuel, etc. Also the post cat O2 was almost pegged out at 0.85 volts constantly. Took it to an exhaust shop where they did the same back pressure test, and at 2500 RPMs, it was almost 6 psi. They replaced both the pre and main cat with just one cat, and now the truck runs great!! Several misfiring incidents over the past several years (corrected now) led to the cats being destroyed. Hope this is helpful info to anyone that watches (and should be!!) watching your channel.
Yeah, your right how dare people make money from your ignorance of mechanical knowledge. They should just have a free service for people who need love and their car fixed... all free, yeah that's how it should be.
findvoltage well there is actually ignorant mechanics that try to solve problems with improper diagnostics, and that’s when they “want money”. She’s obviously not talking about all mechanics, which is why he said WE WANT MECHANICS LIKE HIM. you’re a dumb ass 😂
findvoltage I mind when mechanics make money from their mechanical ignorance...don’t mind one bit if they make money from my ignorance! To boot they’ll fuck up something else _as in this video_ Ill recommend watching it 🤪
Hi, I would consider it pretty normal that the vacuum gauge reads 0 when you try to rev it with a clogged exhaust. In normal operation, intake vacuum is maintained by air flowing in being restricted by the throttle valve. If the restriction is elsewhere, the pressure difference will be elsewhere too. In this case the idle vacuum was already extremely low, which indicates a problem right away. Vacuum gauge can also be helpful in diagnosing a burnt intake valve. Average vacuum will be almost normal, but the gauge will flutter synchronously with the engine speed once per 2 revolutions. In fact I consider the vacuum meter as a very useful tool, but as with all tools it takes some explanation and practice to be used effectively.
I wish you were located in Indiana. This sounds like my car. I have a 2008 Impala. I have replaced the wires and plugs, mass air flow sensor, throttle body, and pedal position sensor. All for it to be sitting in my back yard not able to go over 15 to 20 mph. I have come to find that shops around here even the dealers are shady and just want a quick dollar. Smh
Jayden Shoemaker Yep- all of those are pretty much what you would expect someone who doesn't diagnose a car to guess at. The car in this video had all of those and then some... An easier thing you might be able to arrange- just have someone (or yourself maybe) remove the front O2 sensors. While it will be loud as hell, if you remove the front O2s and the car goes much faster, that alone would be 99.99% confirmation you have a plugged cat
Dude , I can't thank you enough for sharing your knowledge on diagnostics. I'm subbed to your channel and can't stop watching. I'm not a professional mechanic, but lovee to turn wrenches on my own stuff along with family. You have helped give me arsenal of weapons for diagnostics. Actually chasing a very similar issue. Had thought it was vacuum, or 02. Changed the O2 's because the car sat for years and noticed some material on the b2s2. Any how , I'm off to a vacuum test!!! Thank you for saving my money !!!!!!
This old video is great. One thing I learned is clogged cats get really hot. You can diagnose a clogged cat with an infrared temperature laser, ingress and egress pipes, or benchmark in your journal what a normal temp cat would be at, and then take a temperature reading. other videos describe this. Also the exhaust coming out of the pipe will be super hot.
I agree, I am just a backwater mechanic, but I find so many people don't have the slightest clue, even the one's that do this for a living. You have the skill, just figure out what's not causing it, and test to see what it is. I laughed at the frozen piston part. Good job, we need more like you that know how to look outside the box.
Hi. I have Datsun Go, 1200 cc petrol engine. My car recently involved in a car accident. It crash the back of an old car which happen to have stronger body tham my car. So the front of my car is wrecked. I have fixed it. But after 100 km the car loses its power. Seems like the throttle can not reach its maximum power. It stopped at half of the digital indicator. What do you think probably cause it? I ask local repair shop (not doing any test yet) they say "the throttle sensor" cause it. I have spent a lot of money to fix the car after the crash. Please help me to decide what to do next. I dont have much money left :(
Schrodingers Box I am not sure what it means. Because the difference of our language. But I will translate it and give you the update. Thank you for give your time to answer my question. Thats mean a lot.
And the award for world's best mechanic and most stand up person goes to: this guy. Also I really appreciate the fact that you were going to buy the part for her if you were wrong about it
0:58 🤣🤣🤣 I agree. I would love for someone to explain who one would want a 4 cyl that sounds like a V8 and moves like a lawn mower. It’s embarrassing🤦🏾♂️
lol been chasing down little things wrong with my 89 mustang 5.0 and i am broke you vids has been helping me out alot and i find it funny that this is a 2001 sable.. i am using a tps from a 2001 sable, the air box, some temp sensors, grounds, head lights, and this has made my noght not only am i learning more about cars i now know alot of 2000 model sable parts will work for a foxbody
exactly! "Actions speak louder than words!" Too many people that dress like and try to sound like Pros dont come up to your ankle 🤗 After replacing melted catalytic converter the key to ensure the replacement won't melt in short order... I guess "old lady" drove ignoring CEL caused by old plugs.
an easy way to check exhaust restriction is to just unscrew the the upstream o2 sensor and let it dangle. this will tell you right away if you have a restriction. then to tell if it is the cat or muffler , do the same with down stream o2 sensor. make sense??
the logic behind your diagnosis ......."OUTSTANDING", oh by the way we used to joke back in the day about the professional BUNGHOLE REAMER ....WHO KNEW.....
Good thing that the poor lady found you! I agree with ur diagnosis bro, its amazing all the "pros" didnt catch it! It was pretty obvious and well verified by ur tests.. one thing though, yes it may be the catalytic, but swapping a new one in there may yeild a temporary fix, as cats go bad for a reason! and the Cause of the original getting plugged up needs to be addressed or the new one will end up the same way down the line...Ive had new magnaflow cat melt the honeycomb and seen it crumbled inside after 6 months of use... im sure you already are checking into the cause... great vid
It's sad that there are people who say they are "certified" and can't even diagnose a problem. This is exactly why i'd prefer to do the work/diagnoses my self with the help of youtube of course. keep on keepin' on. Your video's are great btw, and have helped me a great deal. thanx
those mechanics knew exactly what they were doing, throwing expensive parts that weren't needed bilking an older lady for expensive labor to fit it and saying "oh gosh gee, guess that wasn't it'. yeah okay, you might have thought it could have been an ISC problem or even something physically wrong with the throttle but unplugging the ISC to see if there was a behaviour change would have confirmed that there wasn't let alone the fact there wasn't a code or even doing basic multimeter tests or a physical inspection of the parts could have confirmed that they were fine. it shouldn't have cost anything other than an hour of labor (which they billed her for anyway for their misdiagnoses) and maybe a $3 gasket to eliminate those as possible causes to which you think "Okay so the engine has no problem with air intake, maybe its not the intake thats the problem" I mean DUH complete hacks
Good video Matt! I've had good success with the vacuum gauge in the past for exhaust restrictions. And as you've done, I do a follow-up with a pressure gauge in the O2 port to finally nail it. Nice work...
They make defouler pipes, to pull O2 sensors back and away and show a good catalytic converter when it's really bad. I don't advocate that kind of repair, but I think it'd be a good way to hook up the gags too. Unlike Matt, I don't happen to have a pipe that's just right. :)
sometimes ignition wires do fix the problem. usually that would cause i misfire and the car will run much worse when you put the engine under a load, and when the weather gets damp it will also effect bad wires. my 2000 GTP was running like total crap. gas mileage was down to 17 mpg and power was way down. i replaced the plugs and wires because it was running much worse when it was snowing out. i also had a misfire P0302 code. i paid $32 for the plugs and wires and did it myself in an hour. i never personally did wires to the car so i had no idea how many miles were on them. they were actually A/C delco wires numbered for the cylinder so they might have been original, im not sure if delco replacement wires come with the cylinder # on them. one of the wires came apart in my hand, they were junk. i could have taken the plugs out checked them over, taken the wires out and checked resistance but im not going to put used stuff back on the car when the whole tune-up was $32. my gas milage also has gone up to 21+ MPG average huge difference that will pay itself off quickly.
You, my friend, are amazing I am hooked on your videos I have an RV with a ford engine.giving me the lean codes that you talk about Been to FOUR mechanics. Yes, parts replaced but error codes still come on. After there cleared, they come on usually a after fifty miles of driving After watching your videos, I am going to try troubleshooting myself Thanks for your excellent videos
Hello I'm five minutes into the video stopped looking diagnosed catalytic converter by what you said curious to finish watching video to see what you find thank you for your help .
You are a Jedi Mechanic! May I be your padiwan.... honestly you make understanding mechanics incredibly easy. I learn so much every video I watch. Thank you
It is a tricky one to figure out. I changed out so many parts to final discover that my truck could inhale fine. Just didnt want to exhale... go figure.😅
Great video on exhaust restriction. Again, your videos make more sense than others. There's always the teacher that matches better how a student thinks. I'm glad I found you and I'm glad you share videos. Don't feel bad about listening to the alternator. I laughed. My mom has those cars and she's about the same age as this car owner. Can I say that? lol. Anyway, it's a resonant point of sound, and even though I know it doesn't mean anything, I always have to look at it when looking under her hood playing, find that sound.
I have the same problem going on with my Brock. Check the exhaust with the thermometer 100°. Check the catalytic converter with the thermometer 470° catalytic converter is clogged. Og, you're a good mechanic. Is it a good thing for an elderly lady? God bless
Really appreciated your intelligence approach . After watching your video my mind is turned back to my Toyota Yaris 1.0L 2000 model old car probably old issue lack ok power forces to paddle reach to 100+ km/h buzzing sound while accelerating fast, LTFT +1.5 at idle , check exhaust seal was ok no cat converter in model , decided to check engine compression and found 3 of spark plugs found oil deposits coil plugged side , that’s was the issue leaks spark plugs seals , got a serviced well tighten well, wow amazing improvement LTFT exact on 0 in idle , it’s all created to you sir the core knowledge way you teaching ❤
Very darn interesting. Though I had watched every video in an attempt to self diagnose my 1996 Nissan Quest performance problem. I’ve had a similar experience, two different “Christian mechanics banged me out of 3k in repairs that did nothing and now I’m tapped. I’m disabled and will have to diagnose and repair it myself without money. Horrible low speed bog, backing off the throttle actually helps a little bit. Only code is a KS, which is under the manifold. Could it actually retard the timing so much that the stupid car won’t even accelerate? Also, it’s amazing how much having the ac on drains power (new compressor). what the heck did I ever do wrong to get stuck with all these problems and have Christian mechanics rob me so badly?!
Well I'll be dammed.... I think I finally found a person that would make me feel like im working with myself... ladies and gentlemen I am far too humbled to be saying this with pride or self centeredness... I'm just speaking my truth. I have felt like there was something very wrong with my style of work. I've been told that I'm a technical freak and a complete overkill. I've been told that I'm a bad mechanic because I act like an "elitist". But I keep to myself verbally and I just do my work....I dont make others feel badly and certainly don't try to make others LOOK badly. God works in funny ways to have my stumble across this video when I wasthinking of abandoning my trade. But this is really how my call to action was meant to be. The best I can be. Thanks for sharing your skills and knowledge of a higher order
Just went through this hell with a 97 explorer. Did not want it to be clogged cats. Did everything else including fuel pump. Finally decided to use a digital meat thermometer. Touched the pipe before and after the cat. One side was about 200 degrees before cat the other side tested 450 degrees before cat! Didn't even need to test after cat! 450 degree at engine side of cat is a clogged cat. easy way to find clogged cat. wish I thought of it sooner. Will never forget. Cat should be about 100 degrees hotter on downstream than it is on engine side of cat. Kudos to my wife with the digital meat thermometer idea.
Frozen #2 piston? What does that even mean? Sounds like a bunch of #2 to me. That's cylinder #4 right there in the front too. The banks go 1-2-3 for bank one, at the firewall. Then 4-5-6 for bank two at the front on those cars.
Funny as soon as you talked about the systems of this car, I said it had an exhaust restriction. I am a very old mechanic and back in the early 70's GM had a very bad exhaust problem. They had a double walled exhaust pipe before the muffler for those who don't know where the exhaust pipe is. Anyway when the car got hot and it was raining and you went through a puddle and hit water onto this pipe it collapsed but only on the inside. If you looked at the pipe it looked fine from the outside but the car didn't go over 25 MPH. After the first 2 I diagnosed the problems in less than 1 minute. No power, hissing noise under the car either moving or not, just trying to rev the engine. Now the vacuum gage is another tell of this problem and will accurately diagnose this problem every time. But after cats came out I found both a clogged cat and a broken apart cat with the insides stuck in the muffler clogging the exhaust. But you are right after you fix this problem you need to find out what caused the cat to go bad.
old video but still relevant. my mom had a 1999 saturn sc2 1.9l4 150,000miles original owner. i was away at college she found a mechanic from facebook he said it needed a new map sensor an new plugs/wires yadayada all this because the car was using oil an had a high idle. it was the PCV valve. a $11 part i would have cleaned it but eh looked like the original
Really enjoy the videos. Please continue as i find them a really good balance of logic, information and encouragement. I especially like the Beavis and Butthead reference in this one.
baz770 Lol, you do realize you you used "logic, information and encouragement" in the same parapgraph as "Beavis and Butthead" lol... that's priceless and actually represents my channel pretty well!!!
Thank you! John 3:16 For God so loved the world that he gave his only begotten Son that whosoever believeth in Him shall not perish but have everlasting life.
Credit due to the mobile douche bag who replaced the throttle body needed for you to run your tests properly. haha I'm just jivin' ya, of course. He probably was missing for two weeks cause his car broke down. hahaha On a side note I'd like, on behalf of all slow readers, to mention the appreciation of the time used for the text inserts in this video. Granted, I personally still needed to pause, haha, its nice to see someone's notice to detail when making a video. cheers buddy
I love a vacuum gauge! They used to make one so you could do early "economaxing" for gas mileage while you were driving. I think GM even installed some from the factory on some mid70, early80's cars.
Do any cars monitor the pressure in the exhaust either directly or indirectly? Is there a trouble code for high exhaust pressure? What are typical codes that might get triggered when the exhaust is restricted?
Check O2 sensors there’s usually a sensor after the converter and it’s mostly there too tell the computer the catalytic converter is working if it’s clogged the voltage should represent somethings up with the converter
Just wanted to mention that with a clogged cat you will most likely have a large negative fuel trim (assuming the front oxygen sensor works). That is what I saw on my Dodge Ram Magnum 5.9, fuel trim was going to -30. That makes sense due to the engine not able to inhale as much air as the ecm expects, therefore the ecm starts trimming down the fuel to match the actual air intake.
Answer to a question I asked on Erico's channel this week. Even a semi clogged cat should show signs of negative fuel trims, as you stated, the air is restricted and the computer cuts the fuel to get stoichiometry.Very sound logical thinking. Must have a peek at the back pressure on my Toyota as negative fuel trims increasing over time.Notice too when I take out the air filter the trims decrease.
I am a ase master 25 years Ive run into this exhaust restriction more than once, ill pull the o2 sensors and run it, that will let the exhaust gas out the o2 sensor holes, if it revs then you have found it, a quick easy test that works for exhaust restriction
ive had recent dramatic success with cleaning out the CATS: I drilled a small hole in the exhaust just before the CAT and while the engine is warm and running, I spray bursts of CARB CLEANING via a straw into the hole. (I do both sides- since I have a GMC van w 2 cats...) The drivability change is very pronounced! I use an entire can. I used a can of intake cleaner also once - w PEA.
I don’t follow- how can drivability increase? Catalytic activity has nothing to do with drivability. What drivability improvement are you experiencing?
I'm confused on your manifold vacuum test. obviously the vacuum indicated on the gauge is low, but under normal operation, should manifold vacuum decrease as you open the throttle?
We have a 2012 Mazda 6 in the shop now. No codes. occasionally throws a 0420 code with a note about warmup. the hissing kind of sucking kind of vaccum cleaner with out the motor sound is remarkable. Later today I will wander under it to see where exactly the restriction is. On newer cars that use a 14mm fitting for the 02 sensor you can you a Dorman Spark plug non fouler to create your "bung hole" fitting. Great video. Nice to see good guys (and little old ladies) winning one.
I am assuming this was a clogged cat? I had one clog on me and will not forget that experience because it left me stranded on the at midnight in january cold spell. The vacuum gauge is a good check. A seat of the pants feel would be going up an incline or if it is worse on a level road, you need to keep pushing down on the gas pedal more and more to keep the same speed. You could also get out and look at the cat after running a few min. like that and you would see it glowing red. I am glad you did mention just remove the o2 sensors and you will notice a drastic improvement right away. Lot of great interesting stuff in your videos-to much actually, it is 3 in the morning and I am still excited watching your videos, I need to get to sleep-lol.
I alway felt like my 4.0L ranger had low power for its engine size, and an average of 10-12mpg with it, and because i have to go full throttle to climb a hill and keep up 90kph, its been like that since i have got it a few months ago, so i alway though it was normal for these engine, but now i will give a try to remove o2 sensors, thanks
I have same problem...only top speed of 20 mph. Could I remove upper oxygen sensor and now if Engine has power and runs almost normal, would that prove there was exhaust restriction ? Believe me, I have addressed everything else in engine compartment. Can I get any encouragement from you ? I could be wrong, but this is pointing to exhaust clogged up. 2001 Buick Lesabra..155K.
I've been working on cars since the 1970's. Former Master ASE tech. You use logic and common sense in your diagnosis. What is wrong with you? Just kidding, I am thoroughly impressed with you.
I have an S10 Blazer with 350 that drops power at 4800 rpm. I have basically replaced the entire fuel system and still does it. Have tried 2 different carbs, 2 different distributors, 3 fuel pumps, ran new fuel line from the tank to the engine, checked the fuel pressure at wot and so on. I noticed today that the people that put the exhaust on smashed the exhaust pipe on both sides to about 1 1/4 inch to go over the trans cross member. I am thinking that would probably create enough back pressure to kill the power at 4800 rpm? Anyway, great video!
What data do you have that it is a fuel system problem? Is this based off fuel trim analysis? off FASTTEC? what is the data you are compiling and interpreting?
The following inquiry arises from someone with undergraduate work in electrical engineering. After earning my Bachelor's degree from SJSU, I furthered my studies as a student of physics at the Center for Educational Research at Leland Stanford Jr. University (CERAS). The aforementioned having sequel as a high school teacher in both physics and chemistry...with both variable and numerous "interludes" with high Tech firms in and around Silicon Valley. I site these credentials as an attempt to emphasize the factual basis of my observations, having scene nothing more than one of your videos, namely (ua-cam.com/video/TxP8SOpOG7Y/v-deo.html). What I see is someone with excellent communication skill, good organizational thought pattern, and good command of the scientific approach to solving things. Your speech is articulate, although at times somewhat of the common folk, "vulgar" if you will...this is not however, in and of it self a bad thing. That being said, if you are not involved in instruction already, and you seem to be, get into it. The field needs people like you, people that possess the skills you may or may not be aware you have. You have the proclivity for instruction, you are personable, you utter clearly, have excellent digression(s), have good command of the link between knowledge and experience..."praxis" if you will. I wonder, were you ever in the Military? Good luck, and, oh yea...great video! rex842015@outlook.com
Usually by driving the car, you can feel the restriction . I diagnosed a few clogged cats simply by driving the car and listening to "bouncy" noises like that intake noisy, the whistling at the EGR due to backpressure building up. But yeah, getting a vacuum gauge to fit in there is 100% proof. There should be no "pressure" in the exhaust system, there should be more vacuum. Oh yeah, and on a car like that, it's going to have either 2 or 4 cats since it's a V6, a hefty repair. It's good to do both at the same time since the other ones are probably not any better.
just curious- how do you know when you have to diagnose vs just guess? For example how do you you know those symptoms were from clogged cat vs DBW system with a fault TPS which would cause same exact symptoms?
Also how are you seeing VACUUM in an exhaust system?? That is impossible, an exhaust system cannot possibly have vacuum. Where are you testing that would see vacuum?
Schrodingers Box I wrote " more vacuum " but i should have been more specific, since on your gauge it was showing 10psi and i ment that it should be a lot lower, but mis used my words. I usually have a car on the hoist and I can hit the cat with a light hammer and hear the material that has caused it to collapse shake. You also hear a different noise from the exhaust when you drive it, thus ruling out any " tps , or "maf" problems. When you see 10 cars a day you will learn a sense. Also chances are if you have tps or maf problems, you would notice them before hitting 2500 rpm or so unless they are very " specific " problems that " only " happen after that, because typically with a clogged cat, you will be stuck at a certain low to mid rpm , that will very slowly climb when you floor it. I guess its called experience
Hey I have a 1991 oldsmobile 88 that just started doing the same after replacing the harmonic balancer. Thing is before replacing the harmonic balancer this car would jump out of gear when I came to a stop. After replacing the harmonic balancer and spark plugs it stop jumping out of gear. It also had plenty of take off power now it like power less on take off. You think it could be exhaust or cat problem?
Great video bud. No codes and certified mechanics guessing. Im stubborn tho and went to cat first. Really tuff to diagnose. Low power but ran good. Shure enuff it was the cat on my f550 v10. 6mpg now at 11. ))
Where would you have attached the back pressure/vacuum gauge hose/pipe fitting behind the cat to test to see about back pressure from the muffler if you would have determined the cat was not clogged? O2 sensor location and pipe fitting made sense to test for back pressure but I’m trying to imagine where you would attach it after the cat to test muffler clog
Now this mechanic you tackled with was ASE certified ??.....and he has "10 years" experience and said it was a frozen piston...what a joke !!!...I don't believe all those other shops misdiagnosed it...most likely all crooks taking advantage of this lady. If I ever go into mobile diagnostics as a part time gig I will call it "Bobs 2 % Mobile Diagnostics". I just watched SMA and Eric O drilled a hole into the exhaust pipe instead of maybe breaking the sensor getting it out and then tack welded the hole when he was done. Good idea if you don't want to shell out money for an new O2 sensor !!...p.s. Have you ever used an infrared thermometer ??...if you measure the welds (recommended area to measure) at the front and back and see around a 150 degree difference or so the cat is plugged. I got one at Harbor Freight for cheap and it's pretty accurate !!
I have a new hero and you are it !! I love the policy you have of buying the part if your wrong. I need your expertise regarding my 2009 corvette base model. Nobody seems to know how to fix my sluggishness of the motor. It is not bad but it is there and a shop told me it is the cam and I have a problem with that as I do not believe so... I will be taking it to a 4th shop this week so they said they will diagnose the problem I hope so.... Can we talk after if they dont repair it
No mechanics like this where I'm at. I currently have a vw cc acting the same way and fortunately caught the guy who put an secondary air pump on it was just going to parts change all over that engine before he ever got to the problem. Sadly I think he knew what it was but hey its 2020 and this year has truly changed people for the worse. I did yank the car from him but not before he removed a perfectly good part and replaced it with a $505.00 part. He literally told me he needed to replace every link in the chain of parts he believed was causing the problem. Told him no and took my car back home. Now it has been diagnosed with a back pressure exhaust issue in addition to a 1 plug and 1 coil replacement. $1958.00 estimate. I have done my own research and was able to find all the parts for 600.00 and will be doing it myself.
i remember first entering the automotive world, wondering was i crazy that so many “master techs” had no clue what they were talking about “you need all 4 oxygen sensors” on my crown victoria lean codes on both banks, i remember thinking i was crazy, cleaned the maf, car ran like a champ. never questioned myself again
wont go over 2500 rpm? car has no power? do you hear a something clanking or broken under the engine when you rev the engine? mine had the same problem. black smoke coming out from the exhaust. checked spark plugs. V6 motor, so one side of engine had plugs all black. had good spark, compression good. Found out that the catalytic convertor was damage and all the stuff inside the converter plugged the exhaust pipe therefore exhaust gases not escaping. after i removed bad catalytic convertor and ran straight pipe, power returned. problem solved. saved over $ 5000 in repairs at mechanic shop.
I can't believe that the lady had to pay for all those bogus repairs. I can only think that these asshats all trained at the 'Scotty Kilmer School of Hit-and-Hope'. New throttle body - unbelieveable!
WOW!!!! I am having a similar problem with my 95 suburban, I am no mechanic but I have been fixing my own vehicles for 40 plus years. I also noticed the "sound" when I accelerated. Everyone I asked never noticed any peculiar sound! A couple of these people were mechanics. Up until I watched your video I thought I was over analyzing the situation, as is often the case with me. (I'm an Aquarius with ADD and OCD. Yeah) So thank you for the video it was well done and very informative!!
i jacked up my car to change a flat tire and i noticed that the new one piece pipe i have is also bigger than the pipe after the catalyst.. Could u tell me if actully this might be the problem .. Btw.. I have an EGR code P0401.. I thought this was the problem and i change the EgR valve but didnt fix nothing and the code light didnt go off .. One of the mechanics told me that whats causing the car to lose power is the EGR passages (ports) are clogged with carbon and others said its the intake manifold gaskit is leaking .. Cleaning the passeges costs more than 300$ so i didnt do it .. I spent alotta money .. Could you help please.
i just found this was my problem with my blazer.... anyway i am 90% sure this is main issue... black plugs,no power,bogs down when i give it gas...I replaced everything else you mentioned... my fingers are crossed...to make sure i will test back pressure in morn... thax
As a mechanic, ive sat in auto dealerships waiting to pick up a part at the parts dept and listened to the service desk presenting lists of "repairs" to poor unsuspecting souls..hearing the diagnosis and the parts and labor pricing is almost painful at times becuz i know what the real time involved for the work done should be and i know what the parts pricing should roughly be... its so sad... people are being fleeced alive, especially old people and women....these shops take full advantage of people ignorance and their helplessness to to their own repairs....integrity and ethics are often absent in this field.
it comes from being continuously in contact with humans that know ZERO about how cars work, the frequent " my car won't start , I think the starter is bad..." mechanic finds it was a burnt fuse, being honest will put maybe $ 20-30 bucks in his pocket, or letting the customer believe he was right, And charging him for the new starter,( which goes straight into his pocket cuz the old one works great and is already installed) ,and the imaginary 3 hours of shop rate in labor to install the imaginary starter, the customer's happy to pay it, and $30 for honesty , vs. $400 -600 for nothing........ they get used to easy money, and in time burn anyone and everyone... I think all mechanics should have three random repairs every 5 years, that are actually employees of the BAR, who bring in cars with issues , pre determined, and report on the mechanics, ability, how he went about diagnosing cause of issue, did more charges than needed appear on the bill, did any of the loose 1 & 5 dollar bills stuffed in the cupholder disappear, or the gold chain half hidden by drivers floor mat?
I just got ripped off by a mechanic who quoted 3 estimates...$500 to get it to run better, $800 to be able to get on the freeway, and $1200 for everything to work right...one mechanic didn't clue in his partner what I was quoted, and when I brought the car in the next day ( having no other option)only the partner was there, I had to ask him , if there wasn't usually something I signed , that had a price and what needed to be repaired? He then asked me what the other guy quoted me....& hastily wrote $500 when he saw the look on my face....I came back to my car having the same exact issues, returning to them, then he told me the ECU needed to be replaced...and he had already ordered it, but wouldn't arrive for 2 days....so I went and got the exact same ECU and brought it to him ,but he now couldn't program it , and sente to his locksmith buddy who did it in 5 minutes, and charged me $300....I did a throte relearn, and the car ran exactly the same...same issues, no change... $500 for vague wiring repairs $65 for diagnostic/engine trouble code printout, which told him the same that I did when I brought the car, $140 for tested used ECU, and $300 to program it......$1000 later, and I'm the same exact place I was before...
I'm going to his shop tomorrow, and I'm so pissed off, I can barely see straight...my Nissan buddy finally gets back to me, so I ask him why would mechanic tell me he found the problem, make the repair, release the car to me only after payment, the problem not be fixed and then state he found the real cause of the problem... "To take your money" , my buddy says......
what do I do next?
Does California Automotive Repair Act , permit a customer blatantly ripped off, to pummel the crooked mechanic until he agrees to fix it right, and right now?
lol bunghole sadly only teens who survived the 90s will understand
shattered79 Beavis and Butthead. “I am The Great Bungholio!
There are no more teens from the 90s.
@@e.v.a.l.s 🙋♂️
Hehhhhhhh i need t-p for my bunghole hehh
"survived" the 90s is correct sir. We all had it so good but we didnt appreciate it enough. lol 90s were the shit
I cannot remember how many times I have paid for parts that were not broken. Sir you are a breath of fresh air. Finally I find a mechanic who does not shotgun a problem with parts until the problem goes away.
Many thanks my friend. Indeed buying parts should be the result of the diagnosis, not the method of it. But it takes knowledge of systems to do the diagnosis and I appreciate the few people like you who are willing to dedicate time and effort to that. In fact it is exactly why I made this channel.
BChrisQq
"If it breaks it needed replacing anyway" ~ Murphy's Law, 1982
02 525 i will not exceed 1000 rpm
@@bridgotslattery4667 you should try it.im sure you'd enjoy it.
I absolutely love your shop policy, more shops need to implement this policy: If you are unable to fix the problem, the parts come out of your pocket. There are too many mechanics out there who just throw parts at a car and pray that it fixes the problem. Good to see techs out there who value the customer's time and money.
@Matt, all of those issues I have been having with my 01 S-10 4.3L were because of a clogged pre-cat, and it blew out the back half of it into the primary cat. Recently, the vehicle would hardly get out of its own way, and on the road it wouldn't accelerate for $hit!! Other than the obvious symptoms, I used an infrared temp gun, and the temp at the back of the pre-cat was 150* lower. The engine was bucking, fuel trims were very lean, was throwing a P0101 code, P0300/P0304 code(s), burning excessive fuel, etc. Also the post cat O2 was almost pegged out at 0.85 volts constantly. Took it to an exhaust shop where they did the same back pressure test, and at 2500 RPMs, it was almost 6 psi. They replaced both the pre and main cat with just one cat, and now the truck runs great!! Several misfiring incidents over the past several years (corrected now) led to the cats being destroyed. Hope this is helpful info to anyone that watches (and should be!!) watching your channel.
I wish there were mechanics like you around everywhere !! All there want is money now and don't care ! :(
Yeah, your right how dare people make money from your ignorance of mechanical knowledge. They should just have a free service for people who need love and their car fixed... all free, yeah that's how it should be.
findvoltage well there is actually ignorant mechanics that try to solve problems with improper diagnostics, and that’s when they “want money”. She’s obviously not talking about all mechanics, which is why he said WE WANT MECHANICS LIKE HIM. you’re a dumb ass 😂
findvoltage I mind when mechanics make money from their mechanical ignorance...don’t mind one bit if they make money from my ignorance! To boot they’ll fuck up something else _as in this video_ Ill recommend watching it 🤪
Agree😔.
Hi, I would consider it pretty normal that the vacuum gauge reads 0 when you try to rev it with a clogged exhaust. In normal operation, intake vacuum is maintained by air flowing in being restricted by the throttle valve. If the restriction is elsewhere, the pressure difference will be elsewhere too.
In this case the idle vacuum was already extremely low, which indicates a problem right away.
Vacuum gauge can also be helpful in diagnosing a burnt intake valve. Average vacuum will be almost normal, but the gauge will flutter synchronously with the engine speed once per 2 revolutions.
In fact I consider the vacuum meter as a very useful tool, but as with all tools it takes some explanation and practice to be used effectively.
i like a vacume gadge+ i hooked one up on my car.
This was a BIG win for you! I'm grateful that i can learn from you.
Excellent Video ... love to see someone who knows what they're doing.
Brilliant ... learned a lot.
Many thanks .
I wish you were located in Indiana. This sounds like my car. I have a 2008 Impala. I have replaced the wires and plugs, mass air flow sensor, throttle body, and pedal position sensor. All for it to be sitting in my back yard not able to go over 15 to 20 mph. I have come to find that shops around here even the dealers are shady and just want a quick dollar. Smh
Jayden Shoemaker Yep- all of those are pretty much what you would expect someone who doesn't diagnose a car to guess at. The car in this video had all of those and then some...
An easier thing you might be able to arrange- just have someone (or yourself maybe) remove the front O2 sensors. While it will be loud as hell, if you remove the front O2s and the car goes much faster, that alone would be 99.99% confirmation you have a plugged cat
Thank you so much. Any advice helps at this point
cat converter
Jayden Shoemaker you fix the car yet
Jayden you ever got you car fix ??
very good video matt, keep up the good work, hopefully the part changers mechanics learn something, thank you ,from ontario ca
Really?? So you run the marathon and you stop a few feets from the finish line. How dum is that
say what? what video are you watching The race ended. i won.
Frozen piston😀, mechanics can be really nasty at times!!
u r a man of integrity +:)
Dude , I can't thank you enough for sharing your knowledge on diagnostics. I'm subbed to your channel and can't stop watching. I'm not a professional mechanic, but lovee to turn wrenches on my own stuff along with family. You have helped give me arsenal of weapons for diagnostics. Actually chasing a very similar issue. Had thought it was vacuum, or 02. Changed the O2 's because the car sat for years and noticed some material on the b2s2. Any how , I'm off to a vacuum test!!! Thank you for saving my money !!!!!!
This old video is great. One thing I learned is clogged cats get really hot. You can diagnose a clogged cat with an infrared temperature laser, ingress and egress pipes, or benchmark in your journal what a normal temp cat would be at, and then take a temperature reading. other videos describe this. Also the exhaust coming out of the pipe will be super hot.
As a training tech in a dealership - thank you for the theory! Throwing darts isn't fair for anyone.
I agree, I am just a backwater mechanic, but I find so many people don't have the slightest clue, even the one's that do this for a living. You have the skill, just figure out what's not causing it, and test to see what it is. I laughed at the frozen piston part. Good job, we need more like you that know how to look outside the box.
Hi. I have Datsun Go, 1200 cc petrol engine. My car recently involved in a car accident. It crash the back of an old car which happen to have stronger body tham my car. So the front of my car is wrecked. I have fixed it. But after 100 km the car loses its power. Seems like the throttle can not reach its maximum power. It stopped at half of the digital indicator. What do you think probably cause it? I ask local repair shop (not doing any test yet) they say "the throttle sensor" cause it. I have spent a lot of money to fix the car after the crash. Please help me to decide what to do next. I dont have much money left :(
Start with seeing if your signal outputs are proportionate to the variable resistance of the potentiometric position on the TPS.
Schrodingers Box I am not sure what it means. Because the difference of our language. But I will translate it and give you the update. Thank you for give your time to answer my question. Thats mean a lot.
This guy is better than at least 90% of the accredited mechanics working at shops
Hi , I am from south Africa you are a life saver you save me thousands, thanks for the advice , you the man
Same here South Africa 🇿🇦 Mpumalanga. He is a life saver for sure. .
And the award for world's best mechanic and most stand up person goes to: this guy.
Also I really appreciate the fact that you were going to buy the part for her if you were wrong about it
0:58 🤣🤣🤣 I agree. I would love for someone to explain who one would want a 4 cyl that sounds like a V8 and moves like a lawn mower. It’s embarrassing🤦🏾♂️
i hit subscribe because of the beevis n butthead impression! lol
lol been chasing down little things wrong with my 89 mustang 5.0 and i am broke you vids has been helping me out alot and i find it funny that this is a 2001 sable.. i am using a tps from a 2001 sable, the air box, some temp sensors, grounds, head lights, and this has made my noght not only am i learning more about cars i now know alot of 2000 model sable parts will work for a foxbody
What a stand up guy! God bless you sir!!
exactly!
"Actions speak louder than words!"
Too many people that dress like and try to sound like Pros dont come up to your ankle 🤗
After replacing melted catalytic converter the key to ensure the replacement won't melt in short order... I guess "old lady" drove ignoring CEL caused by old plugs.
absolutely! how many mechanics do u know who would stand behind their work like that?
an easy way to check exhaust restriction is to just unscrew the the upstream o2 sensor and let it dangle.
this will tell you right away if you have a restriction. then to tell if it is the cat or muffler , do the same with down stream o2 sensor.
make sense??
the logic behind your diagnosis ......."OUTSTANDING", oh by the way we used to joke back in the day about the professional BUNGHOLE REAMER ....WHO KNEW.....
Good thing that the poor lady found you! I agree with ur diagnosis bro, its amazing all the "pros" didnt catch it! It was pretty obvious and well verified by ur tests.. one thing though, yes it may be the catalytic, but swapping a new one in there may yeild a temporary fix, as cats go bad for a reason! and the Cause of the original getting plugged up needs to be addressed or the new one will end up the same way down the line...Ive had new magnaflow cat melt the honeycomb and seen it crumbled inside after 6 months of use... im sure you already are checking into the cause... great vid
I take it you didn't watch till the end
It's sad that there are people who say they are "certified" and can't even diagnose a problem. This is exactly why i'd prefer to do the work/diagnoses my self with the help of youtube of course. keep on keepin' on. Your video's are great btw, and have helped me a great deal. thanx
those mechanics knew exactly what they were doing, throwing expensive parts that weren't needed bilking an older lady for expensive labor to fit it and saying "oh gosh gee, guess that wasn't it'.
yeah okay, you might have thought it could have been an ISC problem or even something physically wrong with the throttle but unplugging the ISC to see if there was a behaviour change would have confirmed that there wasn't let alone the fact there wasn't a code or even doing basic multimeter tests or a physical inspection of the parts could have confirmed that they were fine.
it shouldn't have cost anything other than an hour of labor (which they billed her for anyway for their misdiagnoses) and maybe a $3 gasket to eliminate those as possible causes to which you think
"Okay so the engine has no problem with air intake, maybe its not the intake thats the problem"
I mean DUH
complete hacks
Good video Matt! I've had good success with the vacuum gauge in the past for exhaust restrictions. And as you've done, I do a follow-up with a pressure gauge in the O2 port to finally nail it. Nice work...
They make defouler pipes, to pull O2 sensors back and away and show a good catalytic converter when it's really bad. I don't advocate that kind of repair, but I think it'd be a good way to hook up the gags too.
Unlike Matt, I don't happen to have a pipe that's just right. :)
sometimes ignition wires do fix the problem. usually that would cause i misfire and the car will run much worse when you put the engine under a load, and when the weather gets damp it will also effect bad wires. my 2000 GTP was running like total crap. gas mileage was down to 17 mpg and power was way down. i replaced the plugs and wires because it was running much worse when it was snowing out. i also had a misfire P0302 code. i paid $32 for the plugs and wires and did it myself in an hour. i never personally did wires to the car so i had no idea how many miles were on them. they were actually A/C delco wires numbered for the cylinder so they might have been original, im not sure if delco replacement wires come with the cylinder # on them. one of the wires came apart in my hand, they were junk. i could have taken the plugs out checked them over, taken the wires out and checked resistance but im not going to put used stuff back on the car when the whole tune-up was $32. my gas milage also has gone up to 21+ MPG average huge difference that will pay itself off quickly.
You, my friend, are amazing
I am hooked on your videos
I have an RV with a ford engine.giving me the lean codes that you talk about
Been to FOUR mechanics. Yes, parts replaced but error codes still come on. After there cleared, they come on usually a after fifty miles of driving
After watching your videos, I am going to try troubleshooting myself
Thanks for your excellent videos
Hello I'm five minutes into the video stopped looking diagnosed catalytic converter by what you said curious to finish watching video to see what you find thank you for your help .
If you get a Haynes manuel it will show you what the needle on the vacuum gauge will do when certain conditions exist.
It's generally considered that exhaust systems have 1.5psi max, anything over is considered a clog, higher than 3psi is alot.
For second, at the end note... I genuinely had the image of a dead "cat" (meow) in the muffler... lmao.
You are a Jedi Mechanic! May I be your padiwan.... honestly you make understanding mechanics incredibly easy. I learn so much every video I watch. Thank you
excellent vid! question: could a blocked CAT CON (or muffler) create a LEAN condition, misfires? thanks
"I need a gauge for my bunghole." had to replay it a couple of times, great stuff. Loving the videos! 😎
It is a tricky one to figure out. I changed out so many parts to final discover that my truck could inhale fine. Just didnt want to exhale... go figure.😅
Great video on exhaust restriction. Again, your videos make more sense than others. There's always the teacher that matches better how a student thinks. I'm glad I found you and I'm glad you share videos.
Don't feel bad about listening to the alternator. I laughed. My mom has those cars and she's about the same age as this car owner. Can I say that? lol. Anyway, it's a resonant point of sound, and even though I know it doesn't mean anything, I always have to look at it when looking under her hood playing, find that sound.
I have the same problem going on with my Brock. Check the exhaust with the thermometer 100°. Check the catalytic converter with the thermometer 470° catalytic converter is clogged.
Og, you're a good mechanic. Is it a good thing for an elderly lady? God bless
Is there is a way to give you a thousand LIKE then let me know. Best over thousand of videos I had watched.
Really appreciated your intelligence approach . After watching your video my mind is turned back to my Toyota Yaris 1.0L 2000 model old car probably old issue lack ok power forces to paddle reach to 100+ km/h buzzing sound while accelerating fast, LTFT +1.5 at idle , check exhaust seal was ok no cat converter in model , decided to check engine compression and found 3 of spark plugs found oil deposits coil plugged side , that’s was the issue leaks spark plugs seals , got a serviced well tighten well, wow amazing improvement LTFT exact on 0 in idle , it’s all created to you sir the core knowledge way you teaching ❤
Very darn interesting. Though I had watched every video in an attempt to self diagnose my 1996 Nissan Quest performance problem. I’ve had a similar experience, two different “Christian mechanics banged me out of 3k in repairs that did nothing and now I’m tapped. I’m disabled and will have to diagnose and repair it myself without money. Horrible low speed bog, backing off the throttle actually helps a little bit. Only code is a KS, which is under the manifold. Could it actually retard the timing so much that the stupid car won’t even accelerate? Also, it’s amazing how much having the ac on drains power (new compressor). what the heck did I ever do wrong to get stuck with all these problems and have Christian mechanics rob me so badly?!
Well I'll be dammed.... I think I finally found a person that would make me feel like im working with myself... ladies and gentlemen I am far too humbled to be saying this with pride or self centeredness... I'm just speaking my truth. I have felt like there was something very wrong with my style of work. I've been told that I'm a technical freak and a complete overkill. I've been told that I'm a bad mechanic because I act like an "elitist". But I keep to myself verbally and I just do my work....I dont make others feel badly and certainly don't try to make others LOOK badly. God works in funny ways to have my stumble across this video when I wasthinking of abandoning my trade. But this is really how my call to action was meant to be. The best I can be. Thanks for sharing your skills and knowledge of a higher order
Leave it to Matt, to rescue a fireball elderly lady from the clutches of Snidely Whiplash mechanics........Our Hero!
Just went through this hell with a 97 explorer. Did not want it to be clogged cats. Did everything else including fuel pump. Finally decided to use a digital meat thermometer. Touched the pipe before and after the cat. One side was about 200 degrees before cat the other side tested 450 degrees before cat! Didn't even need to test after cat! 450 degree at engine side of cat is a clogged cat. easy way to find clogged cat. wish I thought of it sooner. Will never forget. Cat should be about 100 degrees hotter on downstream than it is on engine side of cat. Kudos to my wife with the digital meat thermometer idea.
Frozen #2 piston? What does that even mean? Sounds like a bunch of #2 to me.
That's cylinder #4 right there in the front too. The banks go 1-2-3 for bank one, at the firewall. Then 4-5-6 for bank two at the front on those cars.
Thank You! Eric the Car Guy also showed this vac gauge test for exhaust restriction detection.
Funny as soon as you talked about the systems of this car, I said it had an exhaust restriction. I am a very old mechanic and back in the early 70's GM had a very bad exhaust problem. They had a double walled exhaust pipe before the muffler for those who don't know where the exhaust pipe is. Anyway when the car got hot and it was raining and you went through a puddle and hit water onto this pipe it collapsed but only on the inside. If you looked at the pipe it looked fine from the outside but the car didn't go over 25 MPH. After the first 2 I diagnosed the problems in less than 1 minute. No power, hissing noise under the car either moving or not, just trying to rev the engine. Now the vacuum gage is another tell of this problem and will accurately diagnose this problem every time. But after cats came out I found both a clogged cat and a broken apart cat with the insides stuck in the muffler clogging the exhaust. But you are right after you fix this problem you need to find out what caused the cat to go bad.
Who knew Beavis was a great mechanic! Good job
old video but still relevant. my mom had a 1999 saturn sc2 1.9l4 150,000miles original owner. i was away at college she found a mechanic from facebook he said it needed a new map sensor an new plugs/wires yadayada all this because the car was using oil an had a high idle. it was the PCV valve. a $11 part i would have cleaned it but eh looked like the original
I’ve been struggling trying to diagnose this problem with a Mazda 6 v6, bro you earned my respect! You are awesome
Really enjoy the videos. Please continue as i find them a really good balance of logic, information and encouragement. I especially like the Beavis and Butthead reference in this one.
baz770 Lol, you do realize you you used "logic, information and encouragement" in the same parapgraph as "Beavis and Butthead" lol... that's priceless and actually represents my channel pretty well!!!
Thank you!
John 3:16
For God so loved the world that he gave his only begotten Son that whosoever believeth in Him shall not perish but have everlasting life.
Credit due to the mobile douche bag who replaced the throttle body needed for you to run your tests properly. haha I'm just jivin' ya, of course. He probably was missing for two weeks cause his car broke down. hahaha On a side note I'd like, on behalf of all slow readers, to mention the appreciation of the time used for the text inserts in this video. Granted, I personally still needed to pause, haha, its nice to see someone's notice to detail when making a video. cheers buddy
I love a vacuum gauge! They used to make one so you could do early "economaxing" for gas mileage while you were driving. I think GM even installed some from the factory on some mid70, early80's cars.
Haha yes, I recall the gm’s with the “fuel economy guage”
Your new Temperature gadget may also work Pre and Post--Cat too....srry just a random thought...
Do any cars monitor the pressure in the exhaust either directly or indirectly? Is there a trouble code for high exhaust pressure? What are typical codes that might get triggered when the exhaust is restricted?
Perhaps the mobility in 'mobile mechanic ' is their deft ability to leave the scene of the crime under their own power.
I really like the way you wrench.Awsome video man ty
I once just loosened the exhaust, and noticed the car ran.
The car would not even idle, the cat was so bad !
Just saying....
Godspeed.
You are now officially my teacher all i don't know from now on I will be learning from you
Just found this - nice to find another mechanic who gets the left-overs after every other 'expert' has had a go!
Yes what caused the damaged cat? Running rich right? Unburned fuel? But why?
Check O2 sensors there’s usually a sensor after the converter and it’s mostly there too tell the computer the catalytic converter is working if it’s clogged the voltage should represent somethings up with the converter
but remember a clogged cat does not mean the catalyst is nonfunctioning. you still will see a functional signal if catalyst is still active.
Just wanted to mention that with a clogged cat you will most likely have a large negative fuel trim (assuming the front oxygen sensor works). That is what I saw on my Dodge Ram Magnum 5.9, fuel trim was going to -30.
That makes sense due to the engine not able to inhale as much air as the ecm expects, therefore the ecm starts trimming down the fuel to match the actual air intake.
Answer to a question I asked on Erico's channel this week. Even a semi clogged cat should show signs of negative fuel trims, as you stated, the air is restricted and the computer cuts the fuel to get stoichiometry.Very sound logical thinking. Must have a peek at the back pressure on my Toyota as negative fuel trims increasing over time.Notice too when I take out the air filter the trims decrease.
I am a ase master 25 years Ive run into this exhaust restriction more than once, ill pull the o2 sensors and run it, that will let the exhaust gas out the o2 sensor holes, if it revs then you have found it, a quick easy test that works for exhaust restriction
another great video!!
I also thought catalytic converter ...very nice step by step
ive had recent dramatic success with cleaning out the CATS: I drilled a small hole in the exhaust just before the CAT and while the engine is warm and running, I spray bursts of CARB CLEANING via a straw into the hole. (I do both sides- since I have a GMC van w 2 cats...) The drivability change is very pronounced! I use an entire can. I used a can of intake cleaner also once - w PEA.
I don’t follow- how can drivability increase? Catalytic activity has nothing to do with drivability. What drivability improvement are you experiencing?
I'm confused on your manifold vacuum test. obviously the vacuum indicated on the gauge is low, but under normal operation, should manifold vacuum decrease as you open the throttle?
yes exactly. vacuum decreases as you open to atmosphere.
Oh the Passenger side cat when banged sounded like a can full of nuts huhu nuts. The driver side no sound.
We have a 2012 Mazda 6 in the shop now. No codes. occasionally throws a 0420 code with a note about warmup. the hissing kind of sucking kind of vaccum cleaner with out the motor sound is remarkable. Later today I will wander under it to see where exactly the restriction is. On newer cars that use a 14mm fitting for the 02 sensor you can you a Dorman Spark plug non fouler to create your "bung hole" fitting. Great video. Nice to see good guys (and little old ladies) winning one.
I am assuming this was a clogged cat? I had one clog on me and will not forget that experience because it left me stranded on the at midnight in january cold spell. The vacuum gauge is a good check. A seat of the pants feel would be going up an incline or if it is worse on a level road, you need to keep pushing down on the gas pedal more and more to keep the same speed. You could also get out and look at the cat after running a few min. like that and you would see it glowing red. I am glad you did mention just remove the o2 sensors and you will notice a drastic improvement right away. Lot of great interesting stuff in your videos-to much actually, it is 3 in the morning and I am still excited watching your videos, I need to get to sleep-lol.
Lol better than being addicted to crack I guess.
Very good.. I have the same problem on my car... Now I know what to go after.
"I need telemetry for my bunghole"
*honks three times*
"Are you threatening me?"
You must get honesty award I been cheated by 20 mechanics in 6 cars in total loosing 25k
I alway felt like my 4.0L ranger had low power for its engine size, and an average of 10-12mpg with it, and because i have to go full throttle to climb a hill and keep up 90kph, its been like that since i have got it a few months ago, so i alway though it was normal for these engine, but now i will give a try to remove o2 sensors, thanks
I have same problem...only top speed of 20 mph. Could I remove upper oxygen sensor and now if
Engine has power and runs almost normal, would that prove there was exhaust restriction ? Believe
me, I have addressed everything else in engine compartment. Can I get any encouragement from
you ? I could be wrong, but this is pointing to exhaust clogged up. 2001 Buick Lesabra..155K.
Yes that’s absolutely a valid strategy!!
I've been working on cars since the 1970's. Former Master ASE tech. You use logic and common sense in your diagnosis. What is wrong with you? Just kidding, I am thoroughly impressed with you.
Thank you for the compliment!!
I have an S10 Blazer with 350 that drops power at 4800 rpm. I have basically replaced the entire fuel system and still does it. Have tried 2 different carbs, 2 different distributors, 3 fuel pumps, ran new fuel line from the tank to the engine, checked the fuel pressure at wot and so on. I noticed today that the people that put the exhaust on smashed the exhaust pipe on both sides to about 1 1/4 inch to go over the trans cross member. I am thinking that would probably create enough back pressure to kill the power at 4800 rpm? Anyway, great video!
What data do you have that it is a fuel system problem? Is this based off fuel trim analysis? off FASTTEC? what is the data you are compiling and interpreting?
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Usually by driving the car, you can feel the restriction . I diagnosed a few clogged cats simply by driving the car and listening to "bouncy" noises like that intake noisy, the whistling at the EGR due to backpressure building up. But yeah, getting a vacuum gauge to fit in there is 100% proof. There should be no "pressure" in the exhaust system, there should be more vacuum. Oh yeah, and on a car like that, it's going to have either 2 or 4 cats since it's a V6, a hefty repair. It's good to do both at the same time since the other ones are probably not any better.
you didn't diagnose the car then. you used symptoms to come to an inference. There is a huge difference.
Schrodingers Box thats fine, i diagnose a car when necessary, thank you :)
just curious- how do you know when you have to diagnose vs just guess? For example how do you you know those symptoms were from clogged cat vs DBW system with a fault TPS which would cause same exact symptoms?
Also how are you seeing VACUUM in an exhaust system?? That is impossible, an exhaust system cannot possibly have vacuum. Where are you testing that would see vacuum?
Schrodingers Box I wrote " more vacuum " but i should have been more specific, since on your gauge it was showing 10psi and i ment that it should be a lot lower, but mis used my words. I usually have a car on the hoist and I can hit the cat with a light hammer and hear the material that has caused it to collapse shake. You also hear a different noise from the exhaust when you drive it, thus ruling out any " tps , or "maf" problems. When you see 10 cars a day you will learn a sense. Also chances are if you have tps or maf problems, you would notice them before hitting 2500 rpm or so unless they are very " specific " problems that " only " happen after that, because typically with a clogged cat, you will be stuck at a certain low to mid rpm , that will very slowly climb when you floor it. I guess its called experience
Hey I have a 1991 oldsmobile 88 that just started doing the same after replacing the harmonic balancer. Thing is before replacing the harmonic balancer this car would jump out of gear when I came to a stop. After replacing the harmonic balancer and spark plugs it stop jumping out of gear. It also had plenty of take off power now it like power less on take off. You think it could be exhaust or cat problem?
Harry Taylor It could be- what did your diagnostics show?
Vacuum gauges are very good tool to diagnose a exhaust restriction I use it all the time
Love the bevis n butthead reference
Great video bud. No codes and certified mechanics guessing. Im stubborn tho and went to cat first. Really tuff to diagnose. Low power but ran good. Shure enuff it was the cat on my f550 v10. 6mpg now at 11. ))
Where would you have attached the back pressure/vacuum gauge hose/pipe fitting behind the cat to test to see about back pressure from the muffler if you would have determined the cat was not clogged? O2 sensor location and pipe fitting made sense to test for back pressure but I’m trying to imagine where you would attach it after the cat to test muffler clog
I would have used the post cat sensor hole.
Now this mechanic you tackled with was ASE certified ??.....and he has "10 years" experience and said it was a frozen piston...what a joke !!!...I don't believe all those other shops misdiagnosed it...most likely all crooks taking advantage of this lady. If I ever go into mobile diagnostics as a part time gig I will call it "Bobs 2 % Mobile Diagnostics". I just watched SMA and Eric O drilled a hole into the exhaust pipe instead of maybe breaking the sensor getting it out and then tack welded the hole when he was done. Good idea if you don't want to shell out money for an new O2 sensor !!...p.s. Have you ever used an infrared thermometer ??...if you measure the welds (recommended area to measure) at the front and back and see around a 150 degree difference or so the cat is plugged. I got one at Harbor Freight for cheap and it's pretty accurate !!
I have a new hero and you are it !! I love the policy you have of buying the part if your wrong. I need your expertise regarding my 2009 corvette base model. Nobody seems to know how to fix my sluggishness of the motor. It is not bad but it is there and a shop told me it is the cam and I have a problem with that as I do not believe so... I will be taking it to a 4th shop this week so they said they will diagnose the problem I hope so.... Can we talk after if they dont repair it
glad to look at whatever data you have.
No mechanics like this where I'm at.
I currently have a vw cc acting the same way and fortunately caught the guy who put an secondary air pump on it was just going to parts change all over that engine before he ever got to the problem. Sadly I think he knew what it was but hey its 2020 and this year has truly changed people for the worse. I did yank the car from him but not before he removed a perfectly good part and replaced it with a $505.00 part. He literally told me he needed to replace every link in the chain of parts he believed was causing the problem. Told him no and took my car back home. Now it has been diagnosed with a back pressure exhaust issue in addition to a 1 plug and 1 coil replacement. $1958.00 estimate.
I have done my own research and was able to find all the parts for 600.00 and will be doing it myself.
i remember first entering the automotive world, wondering was i crazy that so many “master techs” had no clue what they were talking about “you need all 4 oxygen sensors” on my crown victoria lean codes on both banks, i remember thinking i was crazy, cleaned the maf, car ran like a champ. never questioned myself again
wont go over 2500 rpm? car has no power? do you hear a something clanking or broken under the engine when you rev the engine? mine had the same problem. black smoke coming out from the exhaust. checked spark plugs. V6 motor, so one side of engine had plugs all black. had good spark, compression good. Found out that the catalytic convertor was damage and all the stuff inside the converter plugged the exhaust pipe therefore exhaust gases not escaping. after i removed bad catalytic convertor and ran straight pipe, power returned. problem solved. saved over $ 5000 in repairs at mechanic shop.
I can't believe that the lady had to pay for all those bogus repairs. I can only think that these asshats all trained at the 'Scotty Kilmer School of Hit-and-Hope'. New throttle body - unbelieveable!
Lol “hit and hope” hahahaha!!!
WOW!!!! I am having a similar problem with my 95 suburban, I am no mechanic but I have been fixing my own vehicles for 40 plus years. I also noticed the "sound" when I accelerated. Everyone I asked never noticed any peculiar sound! A couple of these people were mechanics. Up until I watched your video I thought I was over analyzing the situation, as is often the case with me. (I'm an Aquarius with ADD and OCD. Yeah) So thank you for the video it was well done and very informative!!
i jacked up my car to change a flat tire and i noticed that the new one piece pipe i have is also bigger than the pipe after the catalyst.. Could u tell me if actully this might be the problem .. Btw.. I have an EGR code P0401.. I thought this was the problem and i change the EgR valve but didnt fix nothing and the code light didnt go off .. One of the mechanics told me that whats causing the car to lose power is the EGR passages (ports) are clogged with carbon and others said its the intake manifold gaskit is leaking .. Cleaning the passeges costs more than 300$ so i didnt do it .. I spent alotta money .. Could you help please.
i just found this was my problem with my blazer.... anyway i am 90% sure this is main issue... black plugs,no power,bogs down when i give it gas...I replaced everything else you mentioned... my fingers are crossed...to make sure i will test back pressure in morn... thax
Question, what if the intake manifold vacuum is low because of a clogged exhausted, like 14,13 in hg at sea level ?
Then you would need to verify if there is an exhaust restriction with back flow measurement.