PO171 code Pathfinder

[GoJugo]

Have 01 LE 3.5L Pathfinder w/ 99K miles.
Today the SEL came on and have PO171 code . (SEL comes on only on highway)

Engine running well. Just had all spark plugs, one ignition coil, fan belts replaced and checked transmission / transfer case levels.

Could the SEL (w/ code PO171) be related to changing plugs / service. Already had both 02 Sensors replaced a few years ago.

Thanks.

[Towncivilian]

You already posted this twice in the other thread - just be patient and you'll get an answer! In fact I already offered suggestions in the other thread.

[Chuck Tribolet]

P0171 says injection system is lean on the US Passenger's side. FSM says

Possible Cause
I Intake air leaks
I Heated oxygen sensor 1 (front)
I Injectors
I Exhaust gas leaks
I Incorrect fuel pressure
I Lack of fuel
I Mass air flow sensor

FSM has checkout procedure to figure out which. I don't see any of these being caused by your recent work, except for an intake air leak from taking off the throttle body to get at the spark plug underneath it.

[GoJugo]

Took my 01 LE 3.5L Pathfinder to Auto Clinic and they did a quick diagnostic check and handed me the following notes:

REV, scan has set PO171.
Smoke V, visual insp. view fuel trim
STFT 7-8% @ idle LTFT 33% - idle
both banks - same @ idle & cruise
speeds.
Clear code, reset adaptive strategy.

Auto Clinic will check for "intake air leak" and clean the MAF on Tuesday.
They are saying that I most likely will need to have a new MAF installed.
I'm thinking of asking another service shop to install MAF because this shop over charged me on replacing plug.
Had O2 sensors replaced before What if that's the reason for SEL.

Thanks for your guidance.

[Towncivilian]

You can replace the MAF yourself with a tamper-resistant T20 Torx bit and 5 minutes, and you can also use a Maxima MAF for about $90 instead of an exorbitant $442.03 for a Pathfinder MAF.

[GoJugo]

Thanks for link. I called Nissan parts and gave them the part number Maxima MAF part 22680-2Y001. They stated that this part is only for Maxima. Showing no crossover to Pathfinder. They've been selling for over 10 years and have never heard of this part working on Pathfinder.

I can buy at Max MAF at local Nissan dealer for $140 and assume I can return if it doesn't work....

[Towncivilian]

If you search for Maxima MAF you'll find many instances where the Maxima MAF works fine on a 3.5L R50. And yeah, you can probably return it if it doesn't work.

[BeerBoy]

I used the Maxima MAF on my 2001 Pathfinder and it did the trick. Havent had any issues since I replaced it and its MUCH cheaper.

[GoJugo]

Followed Towncivilian's great advise and cleaned the 'MAF Sensor' with 'MAF Sensor Cleaner'. Reset SEL and light hasn't come back on in last two days. Will buy 'Maxima MAF' if SEL comes on again. Thanks.