P0171 System Too Lean bank 1 Chevy Trailblazer "Fixed with no parts"
Вставка
- Опубліковано 16 кві 2018
- Customer Concern: Malfunction Indicator Lamp (MIL) on. Powertrain Control Module (PCM) DTC P0171.
Average Reported Mileage: 100343
P0171 p0174 System Lean Trailblazer "Fixed with no parts"
Mass air flow sensor cleaner: amzn.to/2HbyNJm
Air filter and tune up kit for Chevy Trailblazer: amzn.to/2vt1pbA
Smoke Diagnostic Machine amzn.to/2tbEMoe
Tests/Procedures: 1. Check for a vacuum leak by spraying water around the engine and see if it reacts.
2. At the Mass Air Flow (MAF) sensor connector locate, backprobe and ground the Yellow wire. Reset fuel trims using the scanner and see if Long Term Fuel Trim (LTFT) stay in single digits.
3. Access the fuel system test port, near the fuel tank and fuel filter.
4. Connect a pressure gauge to the port.
5. Fuel pressure should be steady at all loads, 50-57 PSI.
6. Verify that the fuel pressure value is between the range of 50-57 and not dropping under load.
7. Check fuel filter for restriction.
8. Clean the throttle body assembly.
9. Run cleaner through the injectors.
Vehicle Application:
2006 Rainier 4.2
2006 Trailblazer 4.2
2006 Trailblazer EXT 4.2
2006 Envoy 4.2
2006 Envoy XL 4.2
2006 Ascender 4.2
2006 9-7x 4.2
Subscribe here: goo.gl/j1pCfn
Connect with me:
FaceBook: goo.gl/rKg2Bv
Grease Monkey Art Gallery greasemonkeygallery.com/ by The Flat Rate Mechanic
Instagram: goo.gl/NCjRhM
Google Plus: goo.gl/6AyJz3
Website: flatratemechanic.com
For Promotional offers, consulting, training, sponsorships or other inquiries contact me at FlatRateMechanic1@gmail.com
The Flat Rate Mechanic. 25 year ASE Master Automotive Technician and Advanced level ASE certified
The Flat Rate Mechanic is a participant in the Amazon Influencer Program. #P0171 #FlatRateMechanic #DIYAutoRepair Check out The Flat Rate Mechanics Tool Store on Amazon goo.gl/M8MpdC
 :
Disclaimer:
Due to factors beyond the control of The Flat Rate Mechanic, it cannot guarantee against unauthorized modifications of this information or improper use of this information. The Flat Rate Mechanic assumes no liability for property damage or injury incurred as a result of any of the information contained in this automotive repair video. The Flat Rate Mechanic recommends safe practices when working on cars or trucks with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this repair video. Due to factors beyond the control of The Flat Rate Mechanic, no information contained in this automotive repair video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained. - Авто та транспорт
Things I needed in this video. Smoke Diagnostic Machine amzn.to/2tbEMoe
Mass air flow sensor cleaner: amzn.to/2HbyNJm
Air filter and tune up kit: amzn.to/2vt1pbA
The one tool every mechanic should have: amzn.to/2FN2r70
The Flat Rate Mechanic
The Flat Rate Mechanic b
P1200
Would this cause a vehicle not to get thr correct gas mileage? Example tank says 430 miles to E but in reality you get 380 miles to Empty?
Excellent buddy
I did subscribe I hit your thumbs up.
I wish my fix would be easy like that.
Very good video buddy.
Saved me a trip to the shop. Had that hose unhooked on my Envoy as well. Big thanks!
Cool. Glad I could help.
Thanks for a very clear method for diagnosing a problem and demonstrating how to verify and confirm the fix. Great video.
Thanks
Exact hose loose on my 08! THANK YOU for this quick video, I know this is not the fix all the time, but helped in my case. Cleared the code, now time will tell.
Good for checking the oxygen sensors too because they are providing feedback once the vacuum leak is fixed by the short term fuel trim going negative.
I really appreciated the free information mechanic was trying to change me 300 I watched your video did it myself thanks again
The shop probably left it like that on purpose to keep the person coming back spending money.... a lot of these shops don’t want you to have your car running right they greedy
"that will be $200."
Yo... You are an awesome mechanic,
CHECK YOUR O2 SENSOR BY THE MANIFOLD!!!! that fixed my light even tho the code says to replace maf sensor
O2 sensor bank1 I replaced the exhaust manifold gasket had a leak cause p0171 and damaged 02 sensor and caused the exhaust to flex and vibration in my ass lol
08 Envoy 4.2, same code. I watched this video and I checked that same hose and guess what, that same hose was hanging off lol. Same problem. I just bought vehcile so previous owner left it undone.... I saved money as well, which is the best part!!!!!!!!!!
Awesome glad video helped out.
Fixed my 2004 silverado quick thnx to you. It was hose on passenger side valve cover going to intake ducting behind mass airflow..
Great detailed content GOD BLESS
My 'Check Engine' light came on just tonight. In called OnStar and they gave me the same P0171 code. At least I know what to expect when I head in to see a mechanic in a couple of days, and not be fleeced for $$$.
Thank you so much! good video, I will do the test myself.
Thanks was exactly the problem.
This temporary fixed the issue. I’ve tried everything from VVT solenoid, MAF, spark plugs, wires, gas cap, cam sensor, crank sensor, vapor box in the rear, air intake gasket kit. Only thing that helps is fuel additives and high octane gas to get me through emissions. Then it comes back on eventually. I did read it could be a loose timing chain but I would think it’d be something more simple. Wish I could figure this thing out. Lol
Very good video thank you
Useful video
Wow very informative thank you.
Thanks
Thank you found a cracked tip of a Egr vacuum hose easy fix save me a lot time and money
Great help man tks
Another thought, appreciate it.
Thank you for this.
Thanks for this info😊
Thanks for these my car got fix
Mine kept surging on start up to 3k rpms and slowly made its way down before stalling. Guys, don't go buy a smoke detector. I literally hooked up a hair dryer to duct and blew smoke into it. Plugged the other end next to it with a neoprene glove. Worked really well. I located the problem instantly. It was the resonator plug on the right with the metal strap. It was warped and put on wrong. $53 at the salvage yard for the new resonator.
Thanks for this, it's exactly what was wrong with my envoy
I have the same code on our 2003 Chevy venture mini van , the intake manifold gasket was replaced 3 months ago . Dam that engine compartment is tight " 10 pounds of shit in a 2 pound bag " to look for vacuum leaks .
i wish they would go back to making real automobiles again....simple is actually more advanced.....
Finally a good explanation!! Cheers
Love this video
IF the 0171 code means bank 1 only it wouldn't then be a dirty fuel filter or failing pump would it? Wouldn't those cause a 0174 (bank 2) or a generic (both bank) OBD code since it would affect all the cylinders? Thnks... great service and video... I have an '04 explorer... Dont have a smoke machine... Grateful for any answers...
great trick bro - 👌
thanks - 👍
🔥🔥🔥🔥 hit the nail on the button
My e90 is making a loud shinning noise with error code 171. When I release the oil cap, there's lot of suction and resistance to release it and once the cap comes off, the sound disappears. As soon as I put the oil cap back on, the loud noise comes back. What could this be? The code from Autozone says it's the MAF but I changed that 6 months ago and it wasn't needed so I returned it. I also have ISTA but I'm not sure how to use it for this.
Thank you, like an easy fix......................
What can it be if I see smoke around the Throttlebody can it be the Intake manifold or Vale cover, my short term FT is -5 and then goes up to 8 then back down to -3 and long term is at 18 and have a code P0171 lean code
This guy is all over the place..geeez
My 04 3x4 LT is running so rough. Felt like the plugs replaced still shitty. Checked coil packs...good maf sensor good.. But now I'm also blowing fuel pump relays now. Can't figure it out because now It won't run an obd
Good video
I have a question can you purchase any can of smoke so i can run into mas flow senser to see if i have any air leaks anywhere
Thanks I wish I could use that smoke machine.
I've got p2096 and p2098 lean fuel trims bank 1 and 2. Before these codes were set I drove around fine for 6 or 7 miles and then my engine ran really rough and the stabilitrak light was on. I made it home about 5 miles away but the engine was running really rough and thought it would die on me. I pulled all spark plugs and they were fouled so I cleaned them all up and found out that that the pvc tube from the valve cover to the cold air intake was loose and barely in the rubber tube. I zip tied it back into place and re drove the vehicle and it seemed to run fine but I now have those two codes stored. Would this have happened during that first drive or do I now have another issue? Would old gas cause the issue after fixing the vacuum leak?
Genius
just put a volant cold air intake on 05 tahoe... the main air intake tube will not sit flush on manifold. do you think this is why I'm getting these codes system too lean?
Nice Video but Fuel Trim right at zero is a big statement LOL never seen on at 0 before. Just cutting up!
HEY GUY (PLEASE MIND NOT THE CAPITALIZATION. I HAVE BAD EYES) I HAD A BRAND NEW MAF SENSOR INSTALLED IN MY VEHICLE. LIKE A COUPLE DAYS LATER I TRIED GETTING A READING AGAIN. IT SAID NO PROBLEMS BUT THE NEXT DAY THE CHECK ENGINE LIGHT CAME ON AGAIN. THEN I CHECKED THE SCANNER TO IT AGAIN AND IT SHOWED THE SAME CODE WHICH IS THIS ONE. ANY SUGGESTIONS WOULD BE GREATLY APPRECIATED💯 THANKS IN ADVANCE
i hve a po171code dont know if ill fix it however you are a great teacher.
Thank you!
i did fix it,it was o2sensor,what i did is i swaped right to left and left to right and code went to opposite side.
I have the 4.2l6 in my wife's Buick rainier and it have been going dead for no reason and not throwing any codes for 2 3 years and the other day I finally get a code pop up and it's this one, will this be the problem causing the engine to just die wile sitting at a red light
I got this code on my 1999 Oldsmobile Intrigue , any ideas? it make a funny sound when starting but it runs great
What else can I use if I don’t have the smoke machine
So I put a mass sensor on mine because I got this p0171 code . Check engine went off when I changed it. now it’s back on with p0171 code again. What should I do
What if I have the same code and also did a smoke test. But did not find a leak during the smoke test.
What else should I be looking for??
07 envoy here. Same code
This concerns the P0171 code and here is my story for my 2000 Corolla. The code is triggered by the LTFT reaching as high as 38%. STFT stays in the normal range. I have changed the MAF sensor and the upstream 02 sensor. The car's fuel economy is fine and the engine seems to run fine as well. A mechanic said he hadn't seen such a high LTFT reading before and speculated it was the car's ECM. But in talking with a mechanic friend, he was fairly doubtful it was that.
When I recently replaced the 02 sensor, I disconnected the battery to give the system a fresh start. STFT and LTFT started off at 0% but within about 20 minutes of test driving the LTFT was at 19-22% and then not too much longer after that it was back in the 30% range and a pending P0171 code came on in the system.
Might it actually be a vacuum leak? Or could the ECM be the culprit? The car is due to be smogged in April so I kind of need to get this figured out.
Thanks for the video brother my 2001 yukon xl is doing same thing. Conveniently a day after valvoline did my oil change??? Im thinking they did something similar , hopefully its as easy or close to it to fix. Only thing is i had a 02 heater code pop up after the initial lein code?.first it was bank one sensor one, cleared it. Then it was bank 1 AND 2 lein. Cleared it. Then it hit me with a bank one sensor 1 heater switch?? If u get around to this comment, what do u think?
I would keep clearing the light until you get something consistent before chasing you're tall. Sound like the computer is a little confused. You can also look at the fuel trims on a scan tool to see if it is really running lean. If your fuel trim is anything above +10% on eather bank you probably have a problem some were. Fuel trim should always stay around 0 at idle if it taking away fuel, like -10% that would mean its running rich.
Got this code, reached behind the valve cover and found the pcv hose loose. Replaced with new hose. Code has not returned at this time
My 02 trailblazer that stalled on me. Had to get it towed because it wouldn't start back up. Got home, scanned it and got the same code. Hopefully it's a simple fix. Probably not. Have to wait until my mechanic gets back in town to further diagnosis it. But until then, I'll check there hoses and clean the sensor to see what I get.
Bummer, unfortunately it could be a number of things. Typically the hose I found off on this one doesn't just fall off someone was probably checking the air filter or working on it at one point and left it off. In your case it's a good possibility you may just have a bad mass air flow sensor or a large vacuum leak of some sort. But with a p0171 there are a number of different possibilities
What were the LTFT on bank 2 ??...if the LTFT were say 22% the DTC for bank 2 (01074) it would not set a DTC...that would make me change direction as far as troubleshooting...."bank specific" vs. a leak that would set both DTC's....a leaking intake runner on 1 bank vs. a leaking MAF sensor bellows !!
I have a dodge and is doing this same thing I already replaced o2 sensor for both banks and nothing still please help
Hello I have a Toyota Corolla 2000 which is the same problem ( po171 and po302) , what should I do ? Change the intake manifold seal ? or change the spark plug cable for it ? Thanks for your video. It's pretty awesome. I have learnt something else more about it.
I would suspect a bad cyl 2 injectors. But hard saying there is a lot to it.
Inition coil
Hey. Superb video. I have strange problem with short fuel trims. My engine is BMW M54B30. On bank 1 i got +25-28%, but on bank 2 it is ok 0 to 5%. I know that my oxygen sensor after cat on bank1 is dead. Is this can affect on fuel trims?
MAF is working, I checked rubber hoses and there is no cracks.
Help please. Thanks.
No. Pre cat 02s only affect fuel trim. The 02s behind the cats are to measure the efficiency of the Cats by comparing their readings to the first 02s
Hey awesome video. I need your opinion. Basically my car runs fine but it throws the P0171 code and I have replaced everything from spark plugs (original ngk ones) to oem ignition coils (previous ones were faulty) to engine air filter, to cleaning out the fuel injectors so I can rule out coils, injectors, spark plugs. I am chasing goose here I don't know what else to do as I have cleaned my MAF sensor using the cleaner spray and put it back in. I am not sure I even replaced intake vacuum gasket seal. I just don't know what else is causing that code? Could it be fuel pump or some other vacuum leak somewhere? Or could it be o2 sensor? I just don't want to be wasting anymore money fixing things that don't really solve the problem or get rid of the check engine light
Same situation I’m in
My egr valve has a vent hole and smoke comes out of there is that a vacuum leak?
Well, where can I find this on an 01 Cavalier 2.2l SFI engine?
P0171 engine vacuum leak or bad mass air flow sensor or o2 sensor . Running lean bank 1 bank 2
I got a new mass air flow sensor on a chevy aveo LT it's still running lean
I have a 07 impala ss 5.3 getting a code for bank 1 lean and then sometimes I get bank 1 rich code
It could also be a clogged fuel filter
Great tutorial. My 2007 audi a4 giving a p0171. The car starts fine and idles around 1200 rpm then drops to 800 rpm and shakes. I unplugged the brake booster hose and the rpm stays same no change. Shouldn't the rpm rise because I am introducing more unmetered air? I am totally confused. Any help would be greatly appreciated. Thank you
Did you fix it??
So most of the times when you get a lean code you have a vacuum leak? And those fuel trim figures on the tech 2 are at idle correct?
Yes and yes. There are a # of things that can cause a lean condition or a p0171 but yes most common cause would be vacuum leaks.
How can you check without a smoke machine
Flat Rate, what would it mean if the long and short term readings are opposite of the reading you got in this video? I have a 03 tacoma 3.4l with the p0171 code and my fuel trim readings at idle were 1.6 on short and -14.9 on the long. Cleaned MAF and checked for leaks by spraying card cleaner around intake and vac hoses. No change in engine rpm. I suspect weak fuel pump or clogged/bad injectors?
Looks like that to me is a rich condition the computer is actually taking away fuel I would suspect a leaky fuel pressure regulator
Yea, I thought it odd when I got the numbers using the scan tool. A lean condition means, too much air or not enough fuel correct? I did fuel pressure test and got 43 psi. I ruled out fuel pump and filter with that reading. I replaced the upstream air/fuel sensor. Truck seemed better but still had some hesitation punching down on the throttle. Then I realized I had a knock off Denso mass air flow sensor. I bought a real Denso mass air flow sensor and installed that. The truck is running like a top now!
I am thinking , the mass air flow sensor was telling the ecu that , there was less air coming in then what actually was. In turn, the ecu was taking away fuel to balance it out. Excellent video Flat Rate!!! Thanks for the input!
dave jones awesome. Glad you got it fixed
@@FlatRateMechanic i have two trailblazer and neigther have mass air flow sensor, i googled it and i cant any one else talking about one for these vehicles. there is a air temp sensor in the intake tube thing between the air filter and the throttle body and a manifold air pressure sensor in the intake manifold. i wonder if you guys have unreleased gm prototypes?
If I get p0171 and p 1150 at the same time
All these diagnosis people should say right away the very first thing with the p0171 is to check your gas cap and make sure it's tight. that's what I did and that was the problem. I lose gas cap will make your engine computer think your fuel pump is weak or your filter is bad causing the error code for lean bank
That hose is the PCV. Re-connect right away.
Vacuum leak or mass air flow sensor .
Curious why you didn't show the freeze frame.
I didn't need to in this case. It was very clear it was running lean at idle and it was easy to verify the problem. Freeze frame can be a very valuable tool in finding hard to duplicate problems. It this video that was not the case
Hi, I get this code only when I idle for too long, maybe at a drive thru that's taking too long. I get the code and then after a while, sometimes the next day, it disappears. I cleaned the MAF and changed the air filter like you did in the video. Just wondering if it keeps happening it would damage the engine. Ford F-150 2008 4.6.
I got the same thing my 2012 Colorado. I did the throttle body clean. When I drove the truck the next day the idle idle up it took a while for it to idle down and then on the end of the day that's when the check engine light came on I put my code reader on it and it read p0171
Where should I look for the air leak?
New Subscriber 4-2-22
Interesting. Recently my 2015 Malibu had a check engine light on (code P0171 showed up, no other codes) - engine was running fine, no symptoms. The engine is 2.5L DOHC, 4-Cyl. with 64,400 miles. The dealership did a visual test and smoke test and spent 5 1/2 hours on it. Couldn't find a thing and eventually reset the check engine light and gave the car back to me. They told me if the light goes on again, bring it in and they'll continue to work it. They mentioned it could be a bad sensor reading. They didn't know at the time and so it was inconclusive. A lot of time to spend at the dealership for nothing, unfortunately. Since they couldn't find anything, they didn't charge me, otherwise it would have been $199.
Well I'm glad they didn't charge you adleast. Its not uncommon for cars to set lean codes for unknown reason sometimes. Usually a result of a mass air flow sensor getting some dirt on it in most cases. Just be grateful they didn't charge you for something you didn't need. See that all to often. It's a shame and a lot of the reason I started this UA-cam channel so not everyone has to feel like they are at the mercy of there repair shop.
@@FlatRateMechanic Found the problem. Just needed to put gas in from a different gas station than I used before. (Same octane). When I took the car in to Tires Plus for the P0171 code analysis, they couldn't find anything wrong either but gave me their list of culprits for the code and one was "Fuel Quality". After filling up at a different station, the check engine light went out after a day or so.
@@TerryB751 Nice, thanks for the update.
First thing you need to do before you do anything else just make sure your gas cap is tight- and is sealing properly.
Is engine in or off?
if only it were that EZ in real life.
Can a fuel trim be mechanically adjusted on a Buick 2003 3800 V6 engine?
No
i wish they would go back yo making real automobiles again
I keep getting p0171 on my 06 trailblazer along with long cranks before the engibe starts after its warmed up. Cold start it starts right up. Took it to my mechanic and he couldn't find anything at all even with the smoke machine. So he cleared it and gave it back. Now I'm getting it almost every time I start it, it drives fine, everything seems normal but I still keep getting p0171.
My other mechanic buddy says maybe fuel pump or crank sensor, and online other trailblazer owners have said mass airflow sensor or O2. But my mechanic said he found nothing wrong. Any ideas? I have a code reader and had no clue I could look at fuel trims so I'll try that and see what it says. This thing is bugging the crap out of me.
Adjust the the lifters to 0 lash and you be good too go buddy
@@hajrudinkavazovic2231 I have had this issue for years and tried everything. Crank sensor, mass sensor, fuel vapor box in the rear, VVT. If I use fuel additives and the truck feels like it the code will go off. But always comes back. I heard it may be a loose timing chain? Why do you say the valve lash is the issue?
My 01 Chevy 5.3 short term on bank 1 and 2 is 52.3. And on long term bank 1 and 2 it 25.0. Help?
Check to see if breather is unplugged
Cool 😎
I started putting Marvel Mystery fluid in my gas tank every time I fill it up I started getting that code engine running too lean so I stopped adding the Marvel Mystery fluid and the code went away and never came back
That does not surprise me, fuel additives and definitely throw of fuel trim values. Cars are very picky nowadays.
@@FlatRateMechanic thanks that's good to know!!
Can e85 cause this code too ?
Fuel injectors cleaner caused that code to my vehicle
I use stp stuff in a red bottle. Works well. Makes it run way smoother.
I got this code on a 2000 ford 5.4l I I could erase the code and it would drive ok. It turned out to be a unplugged fuel injector
That would also set a misfire code for the specific cylinder .
Could the vacuum leak be in the vent/heater/defrost under the dash, mine pops when the vehicle is off or starting up.
the vent door flaps are electrcal moter actuators. not vaccum ran. sounds like one of your mode doors moters is bad/stuck. can you not swap between defrost and vent and floor vents and or is the pass and driver temps correct and correlate as they should with the temp controls?
I don’t want to go through the trouble of them not knowing the legit issue, when I know the initial signal was 02 sensor. I’m wondering that someone just left my shit unplugged or it’s dirty .. how can I tell ?
alright sir youre good to go thatd be 400$
I had both both codes both banks too lean and I replaced all o2 sensors and codes went away for about 6 months. Now they both came back on. Any idea?
Lean codes can be tricky sometimes, I would really need to see scan tool data in order to point you in the right direction. Tipicaly if it's lean on both Banks it ends up be a vacuum leak or mass air flow sensor probably.
Brother i need a help please i got the short term -7 or -6 i think its good but the long term is 0.0 always!! Not change what is the problem please help and the engine little shaking with rpm ( nissan altima )
Maybe because of o2 sensor??
@@FlatRateMechanic
No vacuum leak found and maf sensor cleaned and replaced. Still having the same codes. I bought 20lbs of tanerite from academy. Going to throw it in the cab and grab my 308. That should do it.
hello Brother 😊 awesome video. i have same code in my car ‘mercedes b klass 2005. the error code is p0171 bank 1 . i had changed throttle body to be able to fix it. but no fixing . same problem is going on. My car is working unstable or continously moving forward and back in stable mode . sometimes it stop for a while . could you please inform me how i i am gonna solve this problem
Nice video where you get these parts to fix it..
Maybee Santa will give you the parts for Christmas lol
I’ve got this code, my check engine light flashes repeatedly. Any ideas anyone?
Ignition coil misfire
Please HELP me out , its been 2 weeks and no mechanic can fix my car.
I am getting code P0171, i have checked all leaks , the shorterm fuel trim is 46.88% , long term fuel trim 18.45%.
Air fuel ratio 26.75 , O2S1 -3.5mA, O2S2 is 0.9V ,
I replied to your post on my Facebook page facebook.com/FlatRateMechanic
Unplugged fuel injector possibly
will the smoke be able to pass closed throttle plates
Yes, because it is never truly closed/may have small hole(s) in it.
What I ended up doing is plugging that tube Because the trailblazers like to shoot oil into the throttle plate and clog it.
I fixed mine with a Carb Cleaner - $25 at autozone
How long did you have to drive ?
@@shellybelle6781 Same question
👍🏿👍🏿👍🏿👍🏿👍🏿👍🏿👍🏿👊🏿
I have this code on a Honda Accord 2003