1997 Pathfinder - sputtering, stalling <1000 rpm & fail safe mode

[Sifujon]

Like the title says, the vehicle has major issues below 1000 rpm right now, and most times will stall out. It will start up again no problem however. This has been going on a few days. The vehicle does have a new: fuel pump, distributor cap, wires, plugs.

The code reader gave me a P0100 MAF code, and a P0325 knock sensor bank 1. The car is also now (very annoyingly) running in fail safe mode and will not go over 2500 rpm I thought clearing the codes would fix this but it definitely didn't. The computer really seems to have an issue with the MAF right now. The car has also been running rough in low idle for quite a few months, and seems to be worse when it's warm and/or humid outside. I saw this might be sensor or distributor related?

I did not see any simple issues under the hood such as loose vacuum lines or broken/disconnected wires. Based off some other threads I'm going to check what the MAF looks like, then see how it runs while disconnected, and then after a good cleaning (provided it isn't obviously broken).

Curious if I'm on the right path or if there's anything else on these vehicles that I may have missed?

Here's the live info from the code reader in case it helps. This was taken during idle in neutral. Most of it is gabbledegook to me as a novice mechanic.

FUELSYS1 CL
FUELSYS2 CL
LOAD_PCT(%) 35.3%
ECT(c) 72
SHRTFT1(%) -25%
LONGFT1(%) 0.8%
SHRTFT2(%) -25%
LONGFT2(%) 0.0%
MAP(kPa) 26
RPM 1400
VSS (km/h) 0
SPARKADV 25
IAT(C) 10
MAF(g/s) 0.11
TP(%) 0
O2SLOC BFS12
O2B1S1 0.760 G
SHRTFTB1S1(%) -8.6
O2B2S1(V) 0.770
SHRTFTB2S1(%) -12.5
O2B2S2(V) 0.7
SHRTFTB2S2(%) 99.2 G
OBDSUP OBDII

Thanks in advance! Please please help cause I"m stumped

[fleurys]

Well looking at your Short term and maf data, you're truck is running ultra lean because it's not seeing any air coming in (0.11 grams per seconds). definitely check if at least the data change when you press on the gas.. if it does then I suspect dirt or oil residu on the filament of the maf. If the data does not change, i suspect a broken wire to your maf.

[Sifujon]

Thank you! I will check after work in about 6 hours and see what's up. I will make sure to update this post in case anyone else has similar issues.

[Sifujon]

So I just cleaned the MAF and the screen, as well as the connectors. Then ran some tests and the MAF seems to be getting 12 V power and ground, but the V reading I get at idle from the signal wire is very low. I looked online and it said it should be around 1 V at idle, and for me it was only around 200 mV, up to 240 mV when revving the engine. The mV did go up smoothly as I revved, but that signal is very low and everything says that means I need to clean it (it's very clean already, I used quite a bit of MAF cleaner and waited for everything to dry). So do I take the plunge and buy a new MAF sensor? I'm probably overthinking this because those damn things are expensive.

[04pathse]

do I take the plunge and buy a new MAF sensor? I'm probably overthinking this because those damn things are expensive.

Other people on this forum have replaced their MAFS with this Maxima MAFS which is much cheaper and they say works just fine for them.

http://www.courtesyparts.com/oe-nissan/226802y001

[Sifujon]

Thank you for that. I will try to get one or two MAF's from a wrecker tomorrow since I would like to have this fixed sooner than later. That price is MUCH better than what I found. Even the cheapest website that I can use in Canada wanted $135. I'll post results again tomorrow. If anyone has other bright ideas please don't hesitate to comment!

[fleurys]

The maxima maf is probably you're best bet (and cheapest).. unless you are able to open the maf sensor itself and see what is going wrong with it...

[04pathse]

I was just thinking that the older Pathfinders/QX4 models may not use the same mafs as the 01-04 so that link for the mafs I posted might not work for your vehicle.

[Sifujon]

Nope sure won't, I just looked up some images of the part. Well that sucks. Still going to try the wrecker first after work, will update with results later this aft.

[Sifujon]

Figured I should close the loop on this thread. I did in fact need a new MAF. I plugged in the new one, cleared the P0100 code, and now it runs just fine.

So if anyone stumbles across this and your Pathfinder is stalling like crazy and gone into limp mode with a P0100 code, you've got power and ground to your MAF connector, and a very, very low reading then it's probably time to buy a new MAF sensor.

I think I mentioned before but I'm in Saskatchewan and the part was hard to find. Local places wanted $250+ for one and had to ship it in. Rockauto had it for around $140 after shipping and only took a few business days.

[fleurys]

Thanks for updating!