The 4.6 in my 03 F150 had the PCV hose connection behind the manifold crumbling. It is a real bugger to change and can't be seen from the front or side at all. Replacing it cured the P0171 and P0174 codes on mine.
Had those codes on my 2001 and found the grommet for the Air Charge Temp. sensor had deteriorated enough that the sensor was sort of falling out and the grommet was no longer keeping air from entering the air tube. Probably the easiest thing it could have been. The hardest part after that, was finding a new grommet the right size.
The 3.8 Liter V-6 in my Windstar threw the same two trouble codes. Apparently it's a common problem with that engine. It's caused by a defect in the material used to make the grommets on the isolator bolts that hold the intake plenum onto the intake manifold. Replacing the isolator bolts solves the problem and it's easy to replace them. A lot easier that replacing the intake manifold gaskets on the engine in the video.
My 2000 5.4 2 valve 157,000 had bad cold rough idle, as you say high fuel trims and when real cold the P0171 P0174. Would clear up as it heated up. Tried to smoke it cold and nothing showed up. First I pulled throttle body off to clean and check that upper gasket as well as all of the vacuum hoses. Put back together, same thing. I should have done this water test but i knew that it was gaskets, common issue due to dissimilar materials plastic intake and aluminum head. I ordered the good Felpro gaskets and when pulled intake saw the dreaded crossover coolant crack as well as gasket separated. Order new Ford intake via amazon as well as motorcraft injector o rings. #7 COP sucks to get out. Had trouble disconnecting the fuel lines with my cheap disconnect plastic rings but i eventually got it after 20 minutes or wrestling. Thing runs like a champ.
Was the intake gasket , had plastic intake with coolant crossover crack. Installed new gaskets and ford intake. New injector o rings and cleaned the injectors
MUST READ! I was going crazy trying to get that error code fixed. I have a 03 v6 4.2 and turns out the leak came from bolt bushings at passenger side intake lower portion. Ford released a service bulletin TSB 04-17-04. Hope this helps for anyone who struggled as much as I did.
This is totally ironic. I just watched your other video (F150 vac leak) LAST NIGHT because I am pulling 2 does on my 2001 Navigator. P0171 & P0174. Thanks Dan!
I'm back from vacation and just enjoyed this short video. I want to catch up on some newer case studies then I'll get back into some lessons. It's good to be back.
On small leaks I've found brake clean and live data helps. When the STFT consistently goes rich, you've found the leak. Leaks too small for those methods? Smoke or like a video of mine where I went crazy DIY with no fancy technique, just look for and replace crusty vacuum lines.
great tip but sure you wouldn't be shorting the coils most common for those codes is a pcv valve tube regardless love you vids tips and tricks definitely a fan keep em coming Dan
@@ScannerDanner let me keep it simple Electrical connections, fuses, poor wiring are all easily damaged by spraying water in an engine compartment this way. Considering the culprit in the video are lean codes, faulty sensor wiring from the PCM, MAF, EGR and any number of pcv valves to bad sensors can create those codes. Spraying them with water can make the problem worse. I guess if you plan on driving though 3 ft of water with no hood then sure a rainstorm would damage your engine.
Great video bro. I'ma try to fix it my self i have had this light on for about a year so i have to fix it before my next smoke test. Like you said it. Fords like to get this things eat up. Lol.
those 5.4's have the deep spark plug water gets down in the coil and shorts had this happen after washing my engine had to remove the coils and boots blow it all out let it dry overnight.
would this cause a hard start issue when engine gets warm..i have a 02 jeep liberty have had that issee with then just the other day it through a lean code p1074 ..
Intake leak (or dirty MAF sensor) tends to affect both bank 1 and 2, not just bank 2 as your code p1074 indicates, though a minor leak on certain intake manifolds might start out only affecting one bank enough to generate the code for that bank. You cannot just guess, the whole point of the video was look at the fuel trims and get the water, or carb cleaner, or a cigar to do a smoke test and see where the problem area is. Actually in the video the problem went the opposite way, that the leak was reduced when the engine warmed up. You stated hard starts but not exactly what it's doing. You could have a head gasket leak on that bank, or possibly a bad temp sensor, even more than one thing wrong, one causing hard start which went on for a while it seems, and now a lean code too. It is good on a vehicle that age to review what is original factory such as fuel filter, spark plugs and wires, though plugs and wires will tend to cause specific cylinder misfires.
currently trying to diag a 99 ford expidition 5.4 sat for a year car came in for a p0171 code, not sure what the last tech did but when I got it long term trims at idle cold engine around 13% (bank 1 and bank 2) driving it i see bank 1 jumps to about 20% bank 2 stays around 10% I have smoked it found a vacuum leak, repaired it but no change. I will try this water trick tomorrow when I go back to work
You can also use a mapp gas torch un lit turn gas on and aim tip at locations you suspect leaks if the engine idles up you have a leak there. Much easier than a sprite bottle 😅
great video scanner danner watch all your videos very interesting hoping if you can help me with my 02 explorer have lean trouble codes have done everything to it smoke the car to find any leaks and find my egr smoking like crazy replaced it and still have trouble codes thanks
Would that also cause a light tap sound at idle? I have 03 gt 4.6 soch 2 valve just replaced stock intake manifold with the pp typhoon one and felpro gaskets. Also we put fuel rails on new plugs and serpentine belt. Ran fine first day next day heard light tick near fuel pressure sensor and check engine light is on with same two codes.
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 ,
Which car is this?.... Did you monitor short and long term fuel trims at idle and when you increase rpm.... How they react? If they tend to correct themselves, meaning bring the values closer to 0, then it's a vacum leak issue If they don't correct them selves and infact get worse, then the issue is related to fuel delivery or MAF
That "water test" is the easiest way to blow coils on a 5.4 and cause more problems and misfires. That is the worst way to diagnose that on a 5.4, unless you like to change coils, all of them you sprayed with a Sprite bottle. Not smart bro.
@@KollynJ no it just went away eventually. I do notice a slight exhaust leak tho. It could honestly have a pinhole in the exhaust manifold or even a crack. Those are so hard to find without taking things apart. If it was a leaking gasket, I guess it just fixed itself. Wish I could help more
I have a vacuum leak but It doesn't show those codes. It only shows misfire in all the cylinders even after replaced coils and spark plugs. Any ideas? 06 rendezvous 3.6L
Hey Paul! This is an off topic suggestion, but you think you can do a video showing your electrical test equipment such as scanners, meters, types of leads, probes, etc..? Would like some recommendations. Thanks!
QUESTION: Would using starting fluid and shooting it around the intake also work? When the idle would change you most likely have found the leak, correct?
This is a MAJOR fire hazard and I do not endorse this method. IF you are going to use a fuel source to find a vacuum leak, you need to be aware of the hazards. (intake back fires can occur, igniting the fuel, spark plug wires and coils can leak and ignite the fuel)
Thanks for the reply I did a fuel pressure test it reads 30 33 PSI then with the brake on I put it on Drive it reads the same 30 33 PSI I put it back in park rev the engine up it almost hits 40 PSI is this normal?
I've got a couple of cylinder misfires. With the P0171 and P0174 are the only codes I get off my OBD2. The intake manifold gasket has been replaced before. Will those codes if not fixed end up constantly misfiring? Also I normally get my parts from Amazon, and the isolator bolts the try to sell with the gasket set doesn't fit my truck. It is a F-150 4.2 2001 model.
Help.. I got the same codes.. 2008 expedition 5.4. High Ltft's don't change on higher rpm. Checked MAF signal ok. Swapped it for s&g. As far as I can tell.. no vac leak. My cheap scanner does a horrible job looking at the o2's. Any suggestions?
Hi Mr.Paul! i am working in a -98 volvo v70.i can not find a wiring diagram for it.should the purge solenoid be fed with 12 v or is it a good number 6v that i have?is it fed by the pcm? hope you understand me 😆 hope to hear from you//
Paul, with all the years you've been in automotive diagnostics, can you please tell me why a simple smoke machine is so damn expensive ? A 1,000 dollars !
@ScannerDanner I've got a PO174 on my 03 Expedition. I've got pics of the freeze frame data from my scan tool. I've checked for intake leaks with no luck. Mine does not get better or worse when warm. If the truck is driven in "normal easy manner" it's hard to notice any problem. Occasionally at a stop light I'll feel a little hickup. Problem occurs under any kind of load. it just won't go. 1/4 throttle going down the road, it simply is hard to get rpms over 2,000 and to get it going. I'd love it if you get the time if I could email you pictures of the freeze frame data and if you could maybe brake the "code" of my issue. Any help would be great! Thanks, Stan...
I've been going though mine, just rebuild the engine last fall. Just replaced the intake gaskets just to rule that out. I've checked hoses, seals everything I've seen online and I can't find it. My ltft doesn't get better as the truck gets warm. I'll have to find a smoke machine.
@@ScannerDanner I'm getting a 171. I instead Stage 2 cams, springs and locked the phasers plus 2 different custom tunes. I'm going to try running with live data see what I can find.
I have a ford expedition 5.4 2002 model. And my battery started reading H when driving.. High voltage sobi got a new battery cause the battery started smelling ugly like rotten eggs. Put new battery in and still reads high voltage what isbthe problem why its doing that now
What is you have both codes PO171 & PO174 and you car / truck still runs fine.... (At least for now it runs fine anyway) At high rpms and at idle I drink a 2000 ford e150 van I really don't have the money $450 - $750 to get it fixed right now. is it safe to continue to drive it? (i'm in a wheelchair and i can't fix any of it myself unfortunately )
How much should it cost me to take it to a shop and have them tell me this same thing? I have 4 codes and I don't have the energy or a smoke machine to figure this out.
freeze frame.. mine says idle rpms 2400 no matter what .. i rev and do test over and same rpms .. how do I change freeze frame ? everyday says the same n I only have.freze frame on tool
I used to use carb cleaner until I had an intake backfire catch the engine bay on fire, in front of a customer, at an unfamiliar shop where I did not know where the fire extinguishers were. 🫨
@@ScannerDanner baby I have a HHR I got the code to go away but I see a little antifreeze so I think I t need a new top but I ear something and it little .on the passages side
very ironic that I'm working on a 2002 expedition 5.4L ...looks like it was pulled from the swamp ......severe misfire and won't go over 45 with no codes ....feels and sounds like it's running on 5 or 6 cylinders
scanner Dan I have a f150 2005 5.4 triton. it had a misfire code on the 2 cylinder and a bank 1 lean code. I have replaced all plugs and coils. and misfires went a way for a few and then it was running worse I was checking fuel trims and looked under the car and seen the cat was glowing red. and I disconnected the cat on passenger side and it started running a little better then too. and has power that it didn't before. but know I still have Bank one lean code and it still runs rough. but my fuel trims aren't high and it's saying coil 6 and 7 have problems but I check them and there sparking just fine any ideas Michael
can you damage an EGR valve by cleaning it with carb cleaner ? i cleaned the one on my expedition and it runs very shitty now ..i put a new egr gasket and the truck smells like fuel , i had a p0171 -174 code before i tried cleaning it ..
usually that is a secondary ignition misfire symptom, the misfire may be there other times too, but you really don't feel it until the torque converter clutch locks up and you lose the cushion of the fluid dampening of the converter. Have your Mode 6 data looked at for which cylinders are showing a misfire (if any, I could be wrong). Any global OBD2 scan tool can give you this data
Hey whats up man ! I have a expedition with 5.4 the truck idles alright litle chaky but not that much when i go and put it in drive it stumbles and almost dies when i put it on revers it complete ly dies and if its in drive and i hit the gas it has no power any help?
If I may ask a quick question related to vacuum leaks and testing them - can a MAP based engine with fuel trims that indicate vacuum leak (as in they get better on higher rpms) still suffer from a vacuum leak when the MAP sensor is showing normal intake vacuum (well, as far as I can guess - don't have specs available) and the IAC is not fully closed yet? I would kinda expect the vacuum to be lower under such circumstances - why wouldn't the ECU just close the IAC more instead of raising the fuel trims or MAP show lower pressure than there should be? I've been struggling to find a leak for weeks (on and off), but with no amount of carb cleaner or water spraying I seem to be able to find one. Yet the fuel trims seem to point to one. Also, I think I can kinda hear some hissing close to throttle body, but again, no dice on finding a leak, so I'm wondering if what I hear is simply the hiss of air running through the throttle body/IAC that's supposed to be there...? Thanks for any advice.
Thanks for the response, much appreciated. It's a 2002 Ford Focus (European) and it does indeed have plastic intake (it's a 1.6 Zetec SE). Didn't want to bother you with details on what was supposed to be a fairly general question. I'm kinda wondering if the elusive vacuum leak - which doesn't seem all that big, if it actually is one - could in fact be caused by leaking throttle plate since there really doesn't seem to be any vacuum leak I could find and I know for a fact the throttle plate isn't exactly sealed. But all that aside, I just don't understand why I'm seeing positive trims when MAP sensor seems to be working fine and reading normal vacuum with IAC also seemingly active and working properly (reads around 31-33 percent open at idle). I'd kinda expect to see one or the other on a MAP engine with a vacuum leak (meaning positive trims at low rpms or normal MAP/IAC readings), but not both at the same time. I can't understand why the ECU would raise trims instead of simply closing the IAC more to compensate for the air coming in through the leak - unless I'm missing something in my understanding of how it all works together (which I guess is quite likely).
BTW, still struggling with that lean idle condition, still can't find the reason. No vacuum leak in sight. It kinda seems to me that the lean idle condition is dependent on intake air temperature - the higher it is, the higher the trim numbers (and the worse the car runs at low rpms). If I unplug the MAP sensor (or TMAP, to be precise), the car idles just fine, the STFT basically cancels out the LTFT (the overall trim is around 3 %, so perfectly fine), the O2 does seem to cycle up and down fine (definitely not suggesting a lean condition). The only thing that's off when I unplug the MAP is that the idle gets a bit higher (around 150 rpm more than normal) - but then again the IAC is also open a few percent more for some reason, so it might be that. Could this perhaps suggest the TMAP is somewhat out of calibration at lower vacuum/higher temperature, causing the ECU to run on leaner base values than it should and having to compensate the offset with higher fuel trim? Or is unplugging the MAP sensor a meaningless test?
So, to finally follow up on this for anyone who happens to stumble upon it in the future (because I hate when people don't follow up) - I believe the issue is finally solved. Even though it exhibited all of the classic symptoms of a vacuum leak, it was actually a MAP sensor off calibration that was causing my lean idle (which I guess makes sense, as my engine is a speed density engine, so it depends on accurate MAP reading, but shouldn't really show higher fuel trims with a vacuum leak like a MAF engine would). Apparently it was reading more or less correct at barometric pressure, but as the pressure decreased, the calibration error was gradually increasing, mimicking the classic vacuum leak symptoms. It was off by something like 5 kPa at idle and even more when e.g. engine braking. So it was kind of a pain to diagnose. Replaced the MAP and the highest fuel trims I've seen so far was like 7 percent overall, which is a LOT better than my previous 25+ (STFT and LTFT combined). I was also experiencing quite a lot of engine knock under light acceleration, and that seems to be a lot better as well overall. So I guess the answer to what can cause a vacuum leak-like fuel trims on a speed density engine is - it might very well be your MAP sensor.
Scanner Danner do u have an email or anywhere to ask you questions that aren't related to any specific video's. I'm trying to get more involved in diagnostics and would like to purchase some equipment but don't want to put my money in the wrong place.
I really like to thank you, your videos are very instructive, I would like to have your opinion about a case, how can you have a lean condition in the long term fuel and a rich one at the same time, meaning in short period . exemple in 2 minute drive the LTF is between min -35 % and max 89% short term fuel between min -100% and max 16% at idling constant LTF -35 , a wave fome STF min -27 max -24 DTC: lean condition Pending Code NB: fuel pump has been changed thank you
Fuel trim analysis should be done during a steady throttle. What are your LTFT numbers at idle and 2500 rpm? A test drive is not needed. Just running in park is fine
I've seen MAF sensor contamination cause a negative number at idle and positive at higher RPMs ua-cam.com/video/CEKjjXNLTjk/v-deo.html If you need more help. Post to my forum scannerdanner.com/forum/post-your-repair-questions-here.html VW's have a different way of displaying their trim numbers and if you are using global data, it can be misleading.
I've got a lean condition P0171 and P0174 with the O2 sensors voltages looking good but the short term fuel trims on both banks second sensors reading at 99.2%. It's a 2004 FX4. The reading is so extreme, I don't know where to start. Any Ideas?
+James Voth The second sensor is downstream and the fuel trim numbers are not used for downstream O2s on your Truck. The 99% reading you see is a bs number and means nothing Focus on your upstream fuel trim numbers
The 4.6 in my 03 F150 had the PCV hose connection behind the manifold crumbling. It is a real bugger to change and can't be seen from the front or side at all. Replacing it cured the P0171 and P0174 codes on mine.
Where is it located ???
Had those codes on my 2001 and found the grommet for the Air Charge Temp. sensor had deteriorated enough that the sensor was sort of falling out and the grommet was no longer keeping air from entering the air tube. Probably the easiest thing it could have been. The hardest part after that, was finding a new grommet the right size.
The 3.8 Liter V-6 in my Windstar threw the same two trouble codes. Apparently it's a common problem with that engine. It's caused by a defect in the material used to make the grommets on the isolator bolts that hold the intake plenum onto the intake manifold. Replacing the isolator bolts solves the problem and it's easy to replace them. A lot easier that replacing the intake manifold gaskets on the engine in the video.
The trims and elevated speed give a good indication of a leak and fast.
Smoke machine definitely. H2O+ Ford COP=misfire!
My 2000 5.4 2 valve 157,000 had bad cold rough idle, as you say high fuel trims and when real cold the P0171 P0174. Would clear up as it heated up. Tried to smoke it cold and nothing showed up. First I pulled throttle body off to clean and check that upper gasket as well as all of the vacuum hoses. Put back together, same thing. I should have done this water test but i knew that it was gaskets, common issue due to dissimilar materials plastic intake and aluminum head. I ordered the good Felpro gaskets and when pulled intake saw the dreaded crossover coolant crack as well as gasket separated. Order new Ford intake via amazon as well as motorcraft injector o rings. #7 COP sucks to get out. Had trouble disconnecting the fuel lines with my cheap disconnect plastic rings but i eventually got it after 20 minutes or wrestling. Thing runs like a champ.
Was the intake gasket , had plastic intake with coolant crossover crack. Installed new gaskets and ford intake. New injector o rings and cleaned the injectors
Do you run any risks by spraying water into the engine bay?
The water test is a good one , i use it a lot now
MUST READ! I was going crazy trying to get that error code fixed. I have a 03 v6 4.2 and turns out the leak came from bolt bushings at passenger side intake lower portion. Ford released a service bulletin TSB 04-17-04. Hope this helps for anyone who struggled as much as I did.
!
what is a service bulletin
@@matadaniel its like an advisory they send out for technicians to be aware of
This is totally ironic. I just watched your other video (F150 vac leak) LAST NIGHT because I am pulling 2 does on my 2001 Navigator. P0171 & P0174.
Thanks Dan!
Did this work for you? The water
well done video. clear sound, very good at explaining.
thanks so much!
Glad to be back to watch your videos Paul. Been following you for years now.
+Richard Gill everything okay?
I'm back from vacation and just enjoyed this short video. I want to catch up on some newer case studies then I'll get back into some lessons. It's good to be back.
Super video Paul ! I haven't had the opportunity to troubleshoot ad intake leak just yet, my water sprayer twitches :)
+Andrea Gili haha
a gentleman and a scholar
Very good. The smook test was also helpful.
Thank you again Paul for a great video.
On small leaks I've found brake clean and live data helps. When the STFT consistently goes rich, you've found the leak.
Leaks too small for those methods? Smoke or like a video of mine where I went crazy DIY with no fancy technique, just look for and replace crusty vacuum lines.
+DE “AutoBravado” Nichols used that method many times myself
great tip but sure you wouldn't be shorting the coils most common for those codes is a pcv valve tube regardless love you vids tips and tricks definitely a fan keep em coming Dan
Havent even watched cideo but I know its a good piece.
Thank you, water bottle is great 👍💯
Holy Hellacious! Are you kidding me. Bring my truck in this shop with PO174 code. Leave with 174 codes because now all my shit is fried!
Lol, water is not going to fry anything. What do you think happens when you drive in the rain?
@@ScannerDanner let me keep it simple
Electrical connections, fuses, poor wiring are all easily damaged by spraying water in an engine compartment this way.
Considering the culprit in the video are lean codes, faulty sensor wiring from the PCM, MAF, EGR and any number of pcv valves to bad sensors can create those codes. Spraying them with water can make the problem worse.
I guess if you plan on driving though 3 ft of water with no hood then sure a rainstorm would damage your engine.
Dude, Great video. I'm going to try this right now. Thanks
Thanks for the video!
This guy is my favorite !
Nice water test dude brilliant and simple
I always did brake cleaner and watched fuel trims change as I spray around hoses and intake.
I used to use a flammable source until I had an intake backfire and caught the engine on fire in front of a customer 😅
tom c. very heipful, I'm going to try it. thanks
Great video bro. I'ma try to fix it my self i have had this light on for about a year so i have to fix it before my next smoke test. Like you said it. Fords like to get this things eat up. Lol.
do I hear idler or belt tensioner pulley bearings screaming?
amazing short video thank you.
those 5.4's have the deep spark plug water gets down in the coil and shorts had this happen after washing my engine had to remove the coils and boots blow it all out let it dry overnight.
are you not worried about water getting to the coils
Nice review of the water technique! That is the same scan tool I use :)
I prefer using Pepsi over a Sprite bottle, I find the caffeine helps me find the vacuum leak much faster. lol
+Ozzstar haha nice
Ozzstar
would this cause a hard start issue when engine gets warm..i have a 02 jeep liberty have had that issee with then just the other day it through a lean code p1074 ..
Intake leak (or dirty MAF sensor) tends to affect both bank 1 and 2, not just bank 2 as your code p1074 indicates, though a minor leak on certain intake manifolds might start out only affecting one bank enough to generate the code for that bank.
You cannot just guess, the whole point of the video was look at the fuel trims and get the water, or carb cleaner, or a cigar to do a smoke test and see where the problem area is.
Actually in the video the problem went the opposite way, that the leak was reduced when the engine warmed up.
You stated hard starts but not exactly what it's doing. You could have a head gasket leak on that bank, or possibly a bad temp sensor, even more than one thing wrong, one causing hard start which went on for a while it seems, and now a lean code too. It is good on a vehicle that age to review what is original factory such as fuel filter, spark plugs and wires, though plugs and wires will tend to cause specific cylinder misfires.
Ozzstar u know some ppl may take u serious and then u fk thier car up.smh
engine running at 20 inch vacuum is the same force on the sealing surface as 10psi net pressure. im sure the smoke machine only uses inch WC.
+Steven Tenney good tip Steven. Thanks!
supper thanks again. may your Blessings be high octane!
I lve your videos , another great one.
What's the desired fuel trim numbers for this truck?
idek
'
currently trying to diag a 99 ford expidition 5.4 sat for a year car came in for a p0171 code, not sure what the last tech did but when I got it long term trims at idle cold engine around 13% (bank 1 and bank 2) driving it i see bank 1 jumps to about 20% bank 2 stays around 10% I have smoked it found a vacuum leak, repaired it but no change. I will try this water trick tomorrow when I go back to work
So trims get worse at higher RPM? That's not a vacuum leak symptom
06 range rover HSE 4.4l with code p0171 only. Any idea what might be the problem?
You can also use a mapp gas torch un lit turn gas on and aim tip at locations you suspect leaks if the engine idles up you have a leak there. Much easier than a sprite bottle 😅
Water is more accurate in most circumstances
I like that little tool can you put a link or information about it . thank you for everything you do for us
Water short out the spark plugs and change engine sound I use carb clearer my great uncle used water and oil to seal in old days
l really enjoyed video thank you matute
Ur intake gasket is leaking Pete!!!
A smoke test is what you need.
Not everyone has one, so I showed a way it can be done without it
Hay Paul this is Marvin I would like to see more uses with the scope.
Common problem with those engines, as well as the coolant pipe in the front developing a leak. What a terrible design.
Great video thanks for sharing :)
great video scanner danner watch all your videos very interesting hoping if you can help me with my 02 explorer have lean trouble codes have done everything to it smoke the car to find any leaks and find my egr smoking like crazy replaced it and still have trouble codes thanks
great master
I have a 4.6 where I thought that the intake leak but it ended up being the O rings on the injectors leaking vacuum .
for sure, another reason I like the water test, you can see it getting sucked in
John McKamy for a week had atap noise then it died out when I left work.. hasno power to even get up driveway.. thanks
Would that also cause a light tap sound at idle? I have 03 gt 4.6 soch 2 valve just replaced stock intake manifold with the pp typhoon one and felpro gaskets. Also we put fuel rails on new plugs and serpentine belt. Ran fine first day next day heard light tick near fuel pressure sensor and check engine light is on with same two codes.
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 ,
Which car is this?.... Did you monitor short and long term fuel trims at idle and when you increase rpm.... How they react?
If they tend to correct themselves, meaning bring the values closer to 0, then it's a vacum leak issue
If they don't correct them selves and infact get worse, then the issue is related to fuel delivery or MAF
That "water test" is the easiest way to blow coils on a 5.4 and cause more problems and misfires. That is the worst way to diagnose that on a 5.4, unless you like to change coils, all of them you sprayed with a Sprite bottle. Not smart bro.
Pendejo
NO WATER !!!!! use brake clean for RPM increase PENDEJO....lol
Id have to agree. Washing my engine started all this for me. Changed plugs, coils, injectors, fixed everything BUT the lean code however.
@@scottskinner577 same here I believe, did you ever figure out you issue?
@@KollynJ no it just went away eventually. I do notice a slight exhaust leak tho. It could honestly have a pinhole in the exhaust manifold or even a crack. Those are so hard to find without taking things apart. If it was a leaking gasket, I guess it just fixed itself. Wish I could help more
Hi Paul, I made my first video. thanks.
I have a vacuum leak but It doesn't show those codes. It only shows misfire in all the cylinders even after replaced coils and spark plugs. Any ideas? 06 rendezvous 3.6L
I know this much as a 5.4 owner. They don't like water on the top of the engine. The coil-on-plug love holding water
Very well said.
Hey Paul!
This is an off topic suggestion, but you think you can do a video showing your electrical test equipment such as scanners, meters, types of leads, probes, etc..? Would like some recommendations.
Thanks!
QUESTION: Would using starting fluid and shooting it around the intake also work? When the idle would change you most likely have found the leak, correct?
This is a MAJOR fire hazard and I do not endorse this method. IF you are going to use a fuel source to find a vacuum leak, you need to be aware of the hazards. (intake back fires can occur, igniting the fuel, spark plug wires and coils can leak and ignite the fuel)
Concern NOTED! Thank you!
Thanks for the reply I did a fuel pressure test it reads 30 33 PSI then with the brake on I put it on Drive it reads the same 30 33 PSI I put it back in park rev the engine up it almost hits 40 PSI is this normal?
I've got a couple of cylinder misfires. With the P0171 and P0174 are the only codes I get off my OBD2. The intake manifold gasket has been replaced before. Will those codes if not fixed end up constantly misfiring? Also I normally get my parts from Amazon, and the isolator bolts the try to sell with the gasket set doesn't fit my truck. It is a F-150 4.2 2001 model.
would a bad intake manifold cause smoke to come out of the tail pipe for a few minutes when starting a 2000 Ford F-150 5.4l? Thanks.
Help..
I got the same codes.. 2008 expedition 5.4.
High Ltft's don't change on higher rpm.
Checked MAF signal ok. Swapped it for s&g.
As far as I can tell.. no vac leak.
My cheap scanner does a horrible job looking at the o2's.
Any suggestions?
Hi Mr.Paul!
i am working in a -98 volvo v70.i can not find a wiring diagram for it.should the purge solenoid be fed with 12 v or is it a good number 6v that i have?is it fed by the pcm?
hope you understand me 😆
hope to hear from you//
Nice video¡¡
What should the short term fuel trim numbers be at idle and higher RPMs?
+Shay “PoorBoy” Linton they should be hovering around 0%. Watch this video, it will help
ua-cam.com/video/oRX2V6_a3dc/v-deo.html
How do you pinpoint the vacuum leak tho?
hi pual is this video accompanied with the sixth edition of your book Engine Performance Diagnostics or not because i haven't in my copy of this book
Paul, with all the years you've been in automotive diagnostics, can you please tell me why a simple smoke machine is so damn expensive ? A 1,000 dollars !
+joeandgod1 go to my forum, there is a thread there where guys are making their own
@ScannerDanner I've got a PO174 on my 03 Expedition. I've got pics of the freeze frame data from my scan tool. I've checked for intake leaks with no luck. Mine does not get better or worse when warm. If the truck is driven in "normal easy manner" it's hard to notice any problem. Occasionally at a stop light I'll feel a little hickup. Problem occurs under any kind of load. it just won't go. 1/4 throttle going down the road, it simply is hard to get rpms over 2,000 and to get it going. I'd love it if you get the time if I could email you pictures of the freeze frame data and if you could maybe brake the "code" of my issue. Any help would be great! Thanks, Stan...
Did you figure it out? Im having same issue on my 03 gt
I've been going though mine, just rebuild the engine last fall. Just replaced the intake gaskets just to rule that out. I've checked hoses, seals everything I've seen online and I can't find it. My ltft doesn't get better as the truck gets warm. I'll have to find a smoke machine.
It may not be a vacuum leak. That isn't the only thing that will cause a 171 or 174 cod3
@@ScannerDanner I'm getting a 171. I instead Stage 2 cams, springs and locked the phasers plus 2 different custom tunes. I'm going to try running with live data see what I can find.
@@Legal_Addiction when you change components in an engine and add custom tunes, this puts you in an entirely different arena, good luck
@@ScannerDanner yeah you definitely got that right! I appreciate the reply. Have a good day!
My concern is getting the smack shocked out of me by stray secondary voltage. What's the chances?
As long as you don't have a pace maker, you'll be totally fine
I have a ford expedition 5.4 2002 model. And my battery started reading H when driving.. High voltage sobi got a new battery cause the battery started smelling ugly like rotten eggs. Put new battery in and still reads high voltage what isbthe problem why its doing that now
What is you have both codes PO171 & PO174 and you car / truck still runs fine.... (At least for now it runs fine anyway) At high rpms and at idle I drink a 2000 ford e150 van I really don't have the money $450 - $750 to get it fixed right now. is it safe to continue to drive it? (i'm in a wheelchair and i can't fix any of it myself unfortunately )
How much should it cost me to take it to a shop and have them tell me this same thing? I have 4 codes and I don't have the energy or a smoke machine to figure this out.
freeze frame.. mine says idle rpms 2400 no matter what .. i rev and do test over and same rpms .. how do I change freeze frame ? everyday says the same n I only have.freze frame on tool
Why would You use water instead of carb/choke cleaner? That water will foul the plugs and blow the coils?
To prevent a fire!! And it's more of a pinpoint test and no, you won't hurt the engine
I always used to use starting fluid haha if the rpms increased you found your leak
I used to use carb cleaner until I had an intake backfire catch the engine bay on fire, in front of a customer, at an unfamiliar shop where I did not know where the fire extinguishers were. 🫨
Sweetttttt.
short 7.8 long 9.4 trim.. what does this mean ??
mine gets worse. rough idle at stops and wants to buck at around 45 mph. code was P0174 on bank 2 only.
PCV valve?
nice, mine was cracked t connection
Hey Teacher I need your help . I am reading a po171 but I can't find it
you have to do more than reading the code
@@ScannerDanner baby I have a HHR I got the code to go away but I see a little antifreeze so I think I t need a new top but I ear something and it little .on the passages side
So it's adding more fuel at idle because it's getting unmetered air.
@scannerdanner do you have a link discussing trim data and how to understand it?
+ken ezzell sure do. Here you go
ua-cam.com/video/oRX2V6_a3dc/v-deo.html
+ken ezzell Man watch the video he linked. It is so informative, its so well done.
Can a bad ground wire cause this, or a missing one????
a bad ground can do a lot of crazy things for sure, but most likely not with lean codes unless the O2 sensors share this ground you are referring to
very ironic that I'm working on a 2002 expedition 5.4L ...looks like it was pulled from the swamp ......severe misfire and won't go over 45 with no codes ....feels and sounds like it's running on 5 or 6 cylinders
you have to use a good scan tool that does power ballance
I have negative LT fuel trim at idle for both banks, and also negative fuel trim at 3000rpm both banks. V6 engine. Rx330. Is this vacuum leak.
you running reach, means you got too much fuel or not enough air. Could be many reasons, i d check maf sensor and fuel system first
scanner Dan I have a f150 2005 5.4 triton. it had a misfire code on the 2 cylinder and a bank 1 lean code. I have replaced all plugs and coils. and misfires went a way for a few and then it was running worse I was checking fuel trims and looked under the car and seen the cat was glowing red. and I disconnected the cat on passenger side and it started running a little better then too. and has power that it didn't before. but know I still have Bank one lean code and it still runs rough. but my fuel trims aren't high and it's saying coil 6 and 7 have problems but I check them and there sparking just fine any ideas Michael
any idea
Michael Starcher I had issue turned To the vacuum on the back on intake manifold 6C324 IIRC,
Michael Starcher
6C324 IIRC, ford part # 30 to 40 at the stealer ship
can you damage an EGR valve by cleaning it with carb cleaner ?
i cleaned the one on my expedition and it runs very shitty now ..i put a new egr gasket and the truck smells like fuel , i had a p0171 -174 code before i tried cleaning it ..
I don't think so, unless you were spraying it in the diaphragm area
What causes a what seems like a missfire at 30 to 45 MPH on 01 Ford sport Trac with the 4.0
usually that is a secondary ignition misfire symptom, the misfire may be there other times too, but you really don't feel it until the torque converter clutch locks up and you lose the cushion of the fluid dampening of the converter. Have your Mode 6 data looked at for which cylinders are showing a misfire (if any, I could be wrong). Any global OBD2 scan tool can give you this data
@@ScannerDanner thanks
Hey whats up man ! I have a expedition with 5.4 the truck idles alright litle chaky but not that much when i go and put it in drive it stumbles and almost dies when i put it on revers it complete ly dies and if its in drive and i hit the gas it has no power any help?
+68 dippin Can't really help you without more direction. Trouble codes? What is fuel pressure? etc
If I may ask a quick question related to vacuum leaks and testing them - can a MAP based engine with fuel trims that indicate vacuum leak (as in they get better on higher rpms) still suffer from a vacuum leak when the MAP sensor is showing normal intake vacuum (well, as far as I can guess - don't have specs available) and the IAC is not fully closed yet? I would kinda expect the vacuum to be lower under such circumstances - why wouldn't the ECU just close the IAC more instead of raising the fuel trims or MAP show lower pressure than there should be?
I've been struggling to find a leak for weeks (on and off), but with no amount of carb cleaner or water spraying I seem to be able to find one. Yet the fuel trims seem to point to one. Also, I think I can kinda hear some hissing close to throttle body, but again, no dice on finding a leak, so I'm wondering if what I hear is simply the hiss of air running through the throttle body/IAC that's supposed to be there...?
Thanks for any advice.
what kind of car? if it has a plastic intake, they are noisy and hiss and sound like vacuum leaks but it is just the intake
Thanks for the response, much appreciated. It's a 2002 Ford Focus (European) and it does indeed have plastic intake (it's a 1.6 Zetec SE). Didn't want to bother you with details on what was supposed to be a fairly general question.
I'm kinda wondering if the elusive vacuum leak - which doesn't seem all that big, if it actually is one - could in fact be caused by leaking throttle plate since there really doesn't seem to be any vacuum leak I could find and I know for a fact the throttle plate isn't exactly sealed.
But all that aside, I just don't understand why I'm seeing positive trims when MAP sensor seems to be working fine and reading normal vacuum with IAC also seemingly active and working properly (reads around 31-33 percent open at idle). I'd kinda expect to see one or the other on a MAP engine with a vacuum leak (meaning positive trims at low rpms or normal MAP/IAC readings), but not both at the same time. I can't understand why the ECU would raise trims instead of simply closing the IAC more to compensate for the air coming in through the leak - unless I'm missing something in my understanding of how it all works together (which I guess is quite likely).
BTW, still struggling with that lean idle condition, still can't find the reason. No vacuum leak in sight.
It kinda seems to me that the lean idle condition is dependent on intake air temperature - the higher it is, the higher the trim numbers (and the worse the car runs at low rpms).
If I unplug the MAP sensor (or TMAP, to be precise), the car idles just fine, the STFT basically cancels out the LTFT (the overall trim is around 3 %, so perfectly fine), the O2 does seem to cycle up and down fine (definitely not suggesting a lean condition). The only thing that's off when I unplug the MAP is that the idle gets a bit higher (around 150 rpm more than normal) - but then again the IAC is also open a few percent more for some reason, so it might be that.
Could this perhaps suggest the TMAP is somewhat out of calibration at lower vacuum/higher temperature, causing the ECU to run on leaner base values than it should and having to compensate the offset with higher fuel trim? Or is unplugging the MAP sensor a meaningless test?
So, to finally follow up on this for anyone who happens to stumble upon it in the future (because I hate when people don't follow up) - I believe the issue is finally solved. Even though it exhibited all of the classic symptoms of a vacuum leak, it was actually a MAP sensor off calibration that was causing my lean idle (which I guess makes sense, as my engine is a speed density engine, so it depends on accurate MAP reading, but shouldn't really show higher fuel trims with a vacuum leak like a MAF engine would).
Apparently it was reading more or less correct at barometric pressure, but as the pressure decreased, the calibration error was gradually increasing, mimicking the classic vacuum leak symptoms. It was off by something like 5 kPa at idle and even more when e.g. engine braking. So it was kind of a pain to diagnose.
Replaced the MAP and the highest fuel trims I've seen so far was like 7 percent overall, which is a LOT better than my previous 25+ (STFT and LTFT combined). I was also experiencing quite a lot of engine knock under light acceleration, and that seems to be a lot better as well overall.
So I guess the answer to what can cause a vacuum leak-like fuel trims on a speed density engine is - it might very well be your MAP sensor.
@@Case_ thanks for all the info!
красава! чел валит
Scanner Danner do u have an email or anywhere to ask you questions that aren't related to any specific video's. I'm trying to get more involved in diagnostics and would like to purchase some equipment but don't want to put my money in the wrong place.
+Rick Waite Post these questions to my forum on www.scannerdanner.com
Thanks!
I really like to thank you, your videos are very instructive, I would like to have your opinion about a case, how can you have a lean condition in the long term fuel and a rich one at the same time, meaning in short period . exemple in 2 minute drive the LTF is between min -35 % and max 89% short term fuel between min -100% and max 16% at idling constant LTF -35 , a wave fome STF min -27 max -24
DTC: lean condition Pending Code
NB: fuel pump has been changed
thank you
Fuel trim analysis should be done during a steady throttle. What are your LTFT numbers at idle and 2500 rpm? A test drive is not needed. Just running in park is fine
LTFT at idle -35%
at 2500 rpm 89%
I need both banks
there is only one bank, it's vw Golf mk5 1.4
I've seen MAF sensor contamination cause a negative number at idle and positive at higher RPMs
ua-cam.com/video/CEKjjXNLTjk/v-deo.html
If you need more help. Post to my forum
scannerdanner.com/forum/post-your-repair-questions-here.html
VW's have a different way of displaying their trim numbers and if you are using global data, it can be misleading.
I've got a lean condition P0171 and P0174 with the O2 sensors voltages looking good but the short term fuel trims on both banks second sensors reading at 99.2%. It's a 2004 FX4. The reading is so extreme, I don't know where to start. Any Ideas?
+James Voth The second sensor is downstream and the fuel trim numbers are not used for downstream O2s on your Truck. The 99% reading you see is a bs number and means nothing
Focus on your upstream fuel trim numbers
Thanks for your reply! Very much appreciated.
So what if your trim numbers didnt improve at 2500 rpms? What would that suggest?
Fuel pressure too low or MAF sensor issue or your two most common issues
Sounds like it has a bad idler or bearing noise too