Obdii Codes

[SG007]

P0171, P0174, P0171 BANK 1&2, P0174 BANK 1&2
O2 sensors or should I clean my MAF sensor and see if that works?
Oh by the way, anybody ever clean their MAF or have pictures? Google doesn't have much to say.
TIA.

[Genopsyde]

yea, clean maf first, it's the cheapest route. just a matter of buying a can of maf cleaner and following the directions on the can.

[SG007]

Well, now I have a clean MAF sensor and 1 missing plastic clip that holds down the air box. Popped off somewhere and I couldn't find it. Oh well. At least I have one left. ha!

The car ran fine and the SES light went away until about 15 minutes later. So the next step would be new O2 sensors, correct? It does the almost-stalling thing when I come to a stop and idles a little rough in D and R. She hasn't stalled on me yet but I'd like to not get to that point.

[Genopsyde]

i don't think a bad o2 sensor would cause a stumble when coming to a stop. I'm gonna hafta think this one over a bit. maybe someone else will chime in?

[wrightz28]

Check for any leaks in the intake tubeing past the MAF to the throttle body, any air unmetered by the MAF will throw the rest of the system into fits.

Other than that, maybe a sticky IAC?

[SG007]

Will do.
The funny thing is the codes come up as 'Oxygen sensors reading running lean, Bank 1 & 2'...so techinically the problem that the computer is picking up isn't the actual sensors, but that the engine is running lean. Oi.
I want my carb back. lmao

[wrightz28]

That's what I'm gettingat, the MAF sees normal airflow when actually more air is entering the intake past it and it doesn't know, hence lean condition indicated by the o2's.

[abaird]

Yeah, lean codes are usually caused by false air entering the system. Make sure your intake ducting is all in place, no exhaust leaks, or vacuum leaks. I know that the intake manifold gaskets in the Gen III truck engines(5.3, 6.0) are notorious for leaking and they are basically the same as an LS1. The one time I saw P0171 that was caused by a dirty MAF, there was no MAF code present(that was on a Lexus so who knows) So the MAF may be sending false readings.