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The picture of the MAF picture installation is confusing. Is that a picture of it looking inside the powerduct? I have the oem duct, If I look inside it just sets in and stops. It even has a alignment nook to attach the maf assembly to the duct. I dont see how this would cause it? I do need a new seal for the air box and one latch is broken, maybe random gusts of air come thru and trigger it? But that is before the maf? I dont know ha.
The Vararam can cause the lean codes. In order to troubleshoot this the OP needs to get a scanner that will let them see what the fuel trims, MAF and O2 sensors are doing otherwise it's a waste of time to try and figure this out. The Vararam air intake needs to be sealed so it doesn't help that there are broken latches and seals not installed properly. Has that been fixed?
No I havnt fixed it. The bottom part latch is broken off and the top connection piece is cracked...id have to buy a whole new system......I can buy a new gasket/filter...
Im not sure how to check O2 sensors but here I did use O2 Sensor test on Innova5310...
O2SB1S1
Rich to Ln Thresh Value .510(v) - Max/Min N/A
Ln to Rich Thresh Value .510(v) - Max/Min N/A
Low V for Switch Value .300 (v) - Max/Min N/A
High V for Switch Value .600 (v) - Max/Min N/A
Rich to Ln Time Value .060 (s) - Min .000(s) Max .252(s)
Ln to Rich Time Value .040(s) - Min .000(s) Max .092(s)
O2SB2S1
Rich to Ln Thresh Value .510(v) - Max/Min N/A
Ln to Rich Thresh Value .510(v) - Max/Min N/A
Low V for Switch Value .300 (v) - Max/Min N/A
High V for Switch Value .600 (v) - Max/Min N/A
Rich to Ln Time Value .040 (s) - Min .000(s) Max .252(s)
Ln to Rich Time Value .032(s) - Min .000(s) Max .092(s)
Last edited by zumbahlenm; Jan 17, 2022 at 09:01 PM.
OK, first thing is you only had a bank specific lean code (P0171) but with 25% long terms on bank 2 you should have a P0174…so with this we are NOT looking at something like a leaky intake runner on one bank but a lean condition involving the whole engine….to rule out a vacuum leak run the engine at 3000 RPM for a few minutes…if you have a vacuum leak your short term numbers will go negative and the long terms will slowly decrease…if numbers increase you have a MAF issue (dirty possibly) or a fuel delivery issue…a weak fuel pump or clogged injectors…MAF reading at .80 is good…I normally read in grams/second and your MAF is just over 6 grams/second…"rule of thumb" is MAF in grams/second should equal the liter displacement of the engine...my car reads about 6.5…your RPM seems low…I idle around 700…next and what stuck out is your MAP in/hg…what is the elevation where you live ??…are you at 8000 feet above sea level ??…do you have a hot cam setup or is your car speed density tuned ??…I’m at sea level in Florida and I read around 9.4 in/hg…at SEA LEVEL atmospheric pressure is 29.9 in/hg so you subtract my 9.4 inches and my intake manifold pressure with a vacuum gauge reads around 20.0 in/hg…29.9 minus 9.4 = 20.5..very close !!…low manifold vacuum can cause lean codes !!…does your scan tool read BARO or MAP in/hg with the key on engine off ??…if so write it down…concerning the O2’s it looks like your in Mode 6…with your scan tool did you enter the year of the car, manufacturer etc…upstream (sensor 1’s) O2’s should switch between 200-800mv and should not be steady either very high or low…can you graph the 02’s instead of trying to read those quickly changing numbers ??…a pic last week of when I had a stuck lean O2 and the other bank was OK…this is what I see so far and it "appears" this may be a vacuum leak with your low manifold vacuum...if it is a vacuum leak you can use some Brake Kleen and your short term fuel trims...spray some Brake Kleen around the intake between the MAF and throttle body, around the PCV, intake runners, and brake booster and if the short terms go NEGATIVE quickly you found the leak !!!...be careful with Brake Kleen which is combustable...I use propane instead.
Not a problem !!…OK, so you do have a P0171/0174….KOEO (Key On Engine Off) you should be close to my numbers in the pic below if you can read them on your scan tool and your upstream O2’s should oscillate from 200-800mv if you can see that…don’t know what “intake work” was done but that’s my first guess !!…if it was removed I’d recheck the torque on the bolts…your MAP will be high like that if you have a vacuum leak so that’s my opinion right now…like I said to diagnose a vacuum leak write down your long and short terms on both banks at idle…raise the RPM to 3000…if it’s a leak your short terms will quickly correct and go negative…your long terms will slowly decrease…if they don’t you have a BIG leak…a Forum member brought his car over here with the same issue and at 3000 RPM fuel trims didn’t budge…he had a pretty big hole in his PCV line and when we took the fuel rail cover off you could hear it…we went to the Zone and bought a short section of hose and then the sun came out and birds started singing !!…so do that and let us know !!…my friend Matt has a great YouTube channel and I’ll include the first of a 7 part series on lean codes…you’re about 135 miles north of me if you’d like to drive down here to have me look at your car !!
I ended up with same results with key on ignition off..not sure if scanner takes it.
I took some Live data..
I tested the short term fuel trims at 3000rpm for 3 min.
STFT both went negative immediately fluctuating from -5 to 0
LTFT B1 Went from 25% to 18%
LTFT B2 Went from 25% to 14.8%
Also the MAP was 10in/hg at idle 635rpm..
The O2 Sensors live data also showed:
B1 S1 / B2 S1 did fluctuate from .2v-.8v
B1 S2 / B2 S2 stayed at .6-.7V
Im not sure which is upstream or down.
Maybe I should come see you ha. I got burned twice on repairs. The first dealer did the intake manifold and oil pan gasket..the oil pan still leaks, maybe the intake does too. The second was a race shop. I brought it for a lean code and they said it was a missfire and the engine fan wasnt working. The wires were brittle so I did change them myself with plugs, but I diagnosed the fan and it worked. The next day the lean code came on and I called back and they said it would be another 150$ diagnose fee. Oh ya I found the pcv hose assembly snapped in half with electrical tape on the pcv valve...which prob made the car overheat when they were doing the high pressure fuel inj cleaning...pshh have to do everything yourself these days.
With the long terms decreasing it sounds like a vacuum leak !!…if you want to bring the car by that would be fine…I’ll put my smoke machine on the car and see where the vacuum leak is…let me know…also your O2 sensors are operating fine !!…sensor 1 are oscillating and sensor 2 are steady !!
Appreciate that, ill let you know. I have to replace the front tie rods and tires before I make a long trip lol!
I smoked it last time and found the smoke coming out of the split pcv assembly...but I did it from the intake and it wasnt really sealed correctly by using a latex glove... I heard people doing it from the brake booster but im not familiar with that location..
Appreciate that, ill let you know. I have to replace the front tie rods and tires before I make a long trip lol!
I smoked it last time and found the smoke coming out of the split pcv assembly...but I did it from the intake and it wasnt really sealed correctly by using a latex glove... I heard people doing it from the brake booster but im not familiar with that location..
OK, so let me know !!…there are a couple locations you can smoke test from but I go in through the intake bellows with a pump that seals up the bellows…kind of looks like a balloon !!..I’m due for new tires myself !!
Well I changed out the suspension on it and got an alignment at the dealer... they did a multi point and said the intake wasn't torqued correctly. They torqued it down and it has been ok for the last few months....now the code is back ahhh ha.
However I was notified of a gas leak....would p0171/p0174 be associated with fuel vacuum leak or is that p0440?...or I am back to smoke test?
Im not sure what im getting into with gas leak but all the parts are discontinued..
Well I changed out the suspension on it and got an alignment at the dealer... they did a multi point and said the intake wasn't torqued correctly. They torqued it down and it has been ok for the last few months....now the code is back ahhh ha.
However I was notified of a gas leak....would p0171/p0174 be associated with fuel vacuum leak or is that p0440?...or I am back to smoke test?
Im not sure what im getting into with gas leak but all the parts are discontinued..
Thanks!
A P0440 is an EVAP system DTC…not the cause of a P0171/0174…2 different systems…now a stuck open EVAP purge valve will give you BOTH lean and rich codes especially after fueling the car…rich codes when the intake is pulling in fuel vapors from the EVAP canister and then you will see lean codes after all those fuel fumes are burned up !!…WOW…you’ve been dealing with this issue for almost a year !!
A P0440 is an EVAP system DTC…not the cause of a P0171/0174…2 different systems…now a stuck open EVAP purge valve will give you BOTH lean and rich codes especially after fueling the car…rich codes when the intake is pulling in fuel vapors from the EVAP canister and then you will see lean codes after all those fuel fumes are burned up !!
Yes ! I've noticed the CEL on after fueling up twice !!!
Yes ! I've noticed the CEL on after fueling up twice !!!
Well then you should hook up your scan tool and view live data after fueling up go for a ride and see if those fuel trims go negative and then positive after those fuel vapors are burned !!
Well then you should hook up your scan tool and view live data after fueling up go for a ride and see if those fuel trims go negative and then positive after those fuel vapors are burned !!
I filled it up with gas and immediately the CEL came on.
Before fill up while driving ranging from ST -5 to +5... LT 11 to 18......at idle ST 0 LT 23-25
After Filing up while driving the first mile ST -12 / -20 to +8...at idle was the same after the mile....
Anything over 10% on the long terms are no good !!…if your short terms go negative like that (PCM “removing” fuel) I’d suspect a stuck open purge…you can remove the EVAP purge line at the intake manifold plug it and see if your long terms slowly decrease as now there is no vacuum leak at the manifold.
