P0171 & 0174 in 01 Pathy

[Daddy Rim]

01 Pathfinder, 165,000 km's

I've been experiencing these error codes, primarily P0171 with the following symptoms:

Upon cold startup the vehicle will surge then seem to bog, surge & bog for about 30 seconds or so, then the engine seems to warm up and not exhibit this problem whilst driving. The engine does seem slightly louder until it warms up a minute or two while driving, but nothing excessive. Doesn't seem to be any exhaust leaks at least any that are evident.

Once the engine has been running for a minute or so the pathy has as much power as it ever has.

My guess was the Mass Air Flow sensor, however I'm wondering if it might be an 02 sensor since once it warms up a tad it runs great.

Thoughts???

[NISTECH]

O2 sensor does not play a part till the engine reaches operating temp[temp gauge about in the middle] You could have a little congestion in your intake. Carbon build up or something like that. Maybe try getting an induction flush or have the base idle checked.

[Daddy Rim]

For anyone who might have these symptoms it turned out to be the MAF which I replaced with a 01 Maxima MAF. So far so good.

Thanks Dave Burnette for the great deal!

[jaedon]

When you replaced your MAF with 2001 maximas' MAF: did you have to have the ecm reprogrammed? how was your stft and ltft?

i tried the maxima maf on my 2001 pathfinder and stft is at -15% and ltft at aroung 32%

-isnt that taking too much air and putting too much fuel?