Another insufferable maf code post
 

Truly sorry for another p010c (Bank2) post and a possible p102 (Bank 1) But that could of been a mistake when switching the mafs around as stated below. Mass air flow (MAF) sensor/volume air flow (VAF) sensor low input - this is leading to some kind of "hickup/misfire" during acceleration, and even full on bogging out after its hot and sits for a few and leading to misfire code p0300.

Engine is totally stock.

We are pretty sure it's not the maf its self (tested a working maf and the two original mafs and switching them all around) my buddy thinks it may actually be at the Ecu.

Do the mafs ground at the Ecu or elsewhere?

Chance the female connector is bad right there?

any other ideas?

Schematics, pin outs, etc are in the FSM. May also have a MAF testing procedure (eg, voltage at different flows).

Yeah I checked the Fsm I don't see any wiring diagrams for it if there is a full Maf wiring diagram somewhere in the Fsm I don't know where it's at since it came as a ton of Pdfs. Deff found the Troubleshoot and voltages ect but nothing showing me where it actually grounds at And from my dumb little Meter it seems ok at the actual maf. Thanks Ark.

It sounds like you found the main things - t/shooting and volts.

Yeah. It can be difficult to find things in the FSM. Many PDF readers will search all PDFs in a folder. Put all the FSM PDFs in a folder and tell your PDF reader to search that folder for "MAF +schematic" and similar.

Ahh yeah was already trying that haha but didn't use "Schematic" But still nothing pulled up, also tried "wiring" before.

I got curious so I tried searching the FSM. Didn't come up with a schematic. :( It's probably in there, I just don't know how to find it.

You can also follow the connector/terminal info. Find the conn/terms at the sensors and follow back to ECM. Pg EC-174 says F31/4 is the ground terminal at the #1 sensor which ends up at F102/68 at the ECM, passing through connectors E106, M6, and M116.

By the way,does the MAF needs cleaning with Contact Cleaner.?

I have cleaned them both, thank you for the post :)

Issue is still present.

Maybe a Computer issue? Maybe I should try cleaning the throttle bodies?

Well threw on TWO brand new but cheap MAFS and cleaned the throttle bodies today. Slightly more responsive but it is still deff not fixed, after driving for a while it is still misfiring for sure, I let it chill for about 20 mins then went out to start it and got some major misfires I could feel shake and pop. Idk what else to do. MAP sensor? Harness shorted out?

Are you still getting the P010C with the new MAFs? If so, I would suspect a wiring problem. If wiring is OK, may be the ECM.

I suggest getting a OBD/CAN monitor that will allow you to watch/record variables.

OP, you bought this car used correct? Have you run a VIN check through CarFax & AutoCheck? I'd look around the ECU for rust or signs of water damage. It's beginning to sound like you bought a flood damaged car. :eek:

Thanks Ark, I Haven't got any codes read since Before the install of the two new Mafs (just a few days ago) CEL Hasn't come on again but it is deff still messed up -

Cold Engine starts and drives mostly fine (some power loss still over 3k rpm/misfires) But after letting it get hot 180~220 it has a chance of bogging and especially if I turn it off and let it sit for a little bit and restart it it runs like **** or stalls almost like it's gas flooded or starved? (This is All the same stuff thats been happening since I originally got the codes)

I'll Try to stop at a friends and see if the same codes are triggering and update here accordingly

Also it's a clean tittle with one minor accident (car was towed out of a small ditch No airbags deployed, very minor damage to one Wheel)

Had codes done by a very nice scanner, It looks like since I changed the Mafs those have not shown back up, the Major codes I got this time were Lean Bank codes 1 and 2

P0171 Lean Bank 1 - This was stored when I ran the codes
P0174 Lean Bank 2 - This showed up after a clear -

Then my car died After letting it get hot for a while, We took a break, I went to leave, and it sputtered and stalled until sufficient time passed it cooled and was able to start.

We are possibly leaning twords a fuel issue now that maf codes are gone.

Failing pump?

Just to be thorough and for knowledge in the post, Here is a full list of codes that first pulled some may be redundant and coincidence from messing with stuff, most are my steering lock (pulled fuse) I think.

B2014 - Chain of Steering lock BCM
B2562 - Low Voltage
B2607 - Lock Relay
B2609 - Lock Status
B260A - Ignition Relay
B26E8 - Clutch Interlock Switch
B2109 - Lock relay off

Engine stuff

P0300 - random multiple Misfires
P0171 - Too lean Bank 1
Po174 - Too lean Bank 2

Thats all I got this time around.

When was the last time you serviced your car battery? It may need distilled water or replacement.

Did you do a re-learn after cleaning the TBs?

No too sure about that battery exactly but I have used two different batteries so far since the issue has happened , they show consistent voltage. And no change of symptoms improving between either battery.

And Which relearn do you speak of exactly? Idle relearn?
Ala: http://nissanhelp.com/diy/z/projects...e_learning.php

Also lslightly off topic, but SouthArk or anyone, do you know What shape fuel Strainer we have? Is it the Moon/Half circle shape? Or square bag shape?

A lean condition is caused by 2 primary things, air & fuel. If the MAF sensor doesn't read the air flow correctly, the ECM compensates by altering the injector duty cycle (length of time open and size of aperture). Some common problems that are starting to appear on 09-11 models are the fuel pump 'hats' breaking off and the pump is laying in the bottom of the gas tank. Phunk (CJM) has a fix for that.

The pictures I've seen in the parts catalog from Nissan is that the strainer is a rectangular 'sock'. But they could be using a 'generic' picture.

My fuel pump hat broke off as well. It is very possible it has happened to OP as well, however I never had any of the issues OP posted about. I just had a messed up gas gauge but none the less still check it out

Thanks Both of you, can I visually see if it's broken easily after opening the fuel compartment behind the seats? My fuel Gauge hasn't shown any issues as far as Iv'e noticed.

I did The full CPU reset relearn procedures - not really any improvement.

Would any of this result in my symptoms of being driveable (but less power and a small stuter at 3krpm) Untill it gets hot and sputter/stalls (most common AFTER turning the car off for a few mins then trying to restart - usually fails to fully start till its cool again)

Yes once you take off all the bs to get to the fuel tank you'll see a white plastic piece. Just unscrew it and pull it out(this is the hat we're referring to it contains you fuel pump and some sensors). You will be able to see if it's broken, however since you said you haven't had any issues with your gas gauge I doubt it's the problem.

I would first start with getting a fuel pressure gauge to be sure you don't have a fuel pump issue. The initial codes were MAF codes so if your fuel is good I'd go back to the MAF sensors. I know you said you replaced them with brand new but cheap ones, were these oem maf sensors you replaced them with?

If the engine is running lean (as per codes you gave above), there are a lot of things that could be the problem - vacuum leak, bad injector, weak fuel pump, bad sensor, faulty ECM, high resistance wiring, etc. Monitoring some of the engine params might give you a hint.

Almost thought it was fixed after a pretty long drive - But nope lol. Did an oil change and threw some injector cleaner in it just for the hell of it. It is running slightly better, but The issues are present and just feel more random though less impactfull....so thats a good thing I guess haha.

I will try to see if I can find a cheap way to test the fuel pressure. So far all I'm seeing is a gauge thats 50bucks. For that price I can basically just buy a new Walbro Pump.

Not sure what else to do other then take it to the dealer shop, and I'm deff not sure how I feel about my local nissan dealer... as far as skill level for problems with the car especially with it being out of warranty.

Any ideas on a way to test fuel pressure without buying the 50$ tester? Or should I just say F it and buy a pump cuz its the same price basically O.o ?

****Update****

Just got off the phone with the dealership - They said they think it's the Air fuel Sensor On the EXHAUST MANIFOLD, passenger side. Can anyone point me to exactly what part this is.

Someone from the dealer read me this part number 226931na0a is this correct?

This it in the pic and heres the one I might buy.

****UPDATE#2****

Replaced the AF sensor Bank 1 with a Denso.

Car is running much better but still not totally fixed.

It's pulling harder and as of right now almost no stumble - still a small stumble seldom at 3.5k rpm but its mostly gone.

After car is hot (200+ degrees) and turned off for a little bit apon restart it is still sputtering but not as bad.

I can't keep nickle and dime parts into this car... -.- Any repair suggestions? Should I replace the driver side AF as well?

Here is a pic of the recommended work from nissan - His tests ONLY showed Bank 1 issue af though recommends changing both banks.

just an update....after I changed out my pcv valves I now see my fuel trims in opposite positions at startup. before changing out the pcv valves on startup my LTFT would be at -10.94% with STFT trending towards +9%. once warm with the old pcv valves my LTFT would stay stuck at -10.94% with STFT at around +3% or close to 0%, when I would snap the throttle open LTFT would stay pinned at -10.94%. now with new PCV valves on startup my LTFT is now at +9% and STFT is at a -10% until warm up when LTFT seems to settle at around -8% and STFT seems to settle around 0%, interesting to note however is now when I snap the throttle open all fuel trims line up at 0% or close to it and go back to the previous figures when let back down to idle. not to jump to any conclusions, but to me at least the old PCV valves seem to have been the culprit when it came to the fuel trims seeing as everything is now lining up with the new PCV valves. oh and car now idles smoothly without the stumbles and drops in RPM I was seeing before.

****UPDATE#3****

Installed an oil cooler - can confirm it still has the same issues but now I can rule out that having 200+ degree oil temp has nothing to do with it.

They said i'm running a constant 30psi, but isn't that TOO low? The fsm says 51psi @ idle. And WHo knows how long he tested or if he tested at load or during the issue.

Issue with my Fuel pressure regulator maybe?

Is there anyone in North East Ohio area that can truly figure out this issue... ugh. I'm going crazy.

*** update # who cares...***

Nissan agreed that 30psi was too low and recommends replacing the fuel pressure regulator.

...can't seem to find them for sale anywhere.

From dream car to nightmare.

Maybe this is the part they are referring to? Seems to come up a lot when you search for fuel pressure regulator.

https://www.z1motorsports.com/fuel-d...hr-p-9194.html

Edit: looks like the fuel pressure regulator is built into the fuel pump assembly so i guess time for a new fuel pump?

Thanks Z_ealot - Yeah this is just a pulse damper (they help regulate the pressure at the rails) there should be 2 of them and they are right in the engine bay one is seen easily near the left intake. They are cheap and I might replace just to see if it helps, but as far as nissan dealer is concerned they said im getting 30psi, which would point more to the pump/basket/regulator/lines as far as I know. . . THis issue is driving me nuts and obv Nissan is only shooting answers in the dark - feel like they cant really diagnose it correctly.

If you're only seeing 30psi of fuel pressure my first guess would be the pump and not the reg (Though I am no expert here)... as mentioned in your other thread I don't believe the reg is serviceable without replacing the basket... the pump, however, is serviceable... I sold my used OEM pump (just the pump, no assembly) on ebay for like $10. I also bought an entire assembly with broken hat from a wreck yard locally for $50 when I needed some odd parts off it. You could find something like that and swap your non-broken hat onto it - this solution would also replace the reg at the same time.
Brand new OE replacement pumps (again, just the pumps) are $30 on ebay... I dont know anything about the quality of them...just trying to give you options.

Keep in mind if you go the walbro route, you will have to do some additional mods to the basket to get it working. CJM sells a kit.

Sounds like great logic to me.

Personally, I wouldn't take the dealership's word for it (unless they were going to fix it under warranty). I'd check the fuel pressure myself or get a 3rd party to do it.

Thanks for the input - I'll see if I can find CJM's kit, was thinking of going walboro. And I might see If I can find a whole basket like you said. All I know is i'm just shooting parts at this thing without knowing what truly is the issue since nissan can't seem to give a 100% answer lol.

ANyone know if a basket from a 2016 Nismo will work haha? Or is it different in some way?

Should swap right in AFAIK.

Awesome supposedly found a whole unit with the Oem pump still in it from a 16 nismo for 80 bucks (scary cheap)... hope I can just drop it in. If it isnt broke or something strange it will at least rule out any issues from the tank if the problem persists.

If it isn't the issue you can probably resell it without any loss.