Code Reader - Lean System?

[wekilled]

All:

Thought I'd get some advice from the collective: I am getting ODB2 codes P0171 lean system bank 1, and P0174.

Is this an O2 Sensor Problem? Thoughts?

-Doug

[Ldub]

Two other possibilities are:

Intake gaskets

Clean MAF sensor

Another thought, I had the same codes & thought for sure it was intake gasket related.
I replaced my intake gaskets (which were visibly cracked) only to throw the same codes after putting everything back together.
A little more digging & I found that the little sensors in the MAF were covered in a sooty residue from K&N oil. A quick blast with some MAF cleaner & I've been CEL free for almost a year.

[Techy-D]

Mine started with the same codes soon after I got it. I found vacuum leaks around my fuel injectors. I could hear it sucking and could almost stop it when I moved the fuel rail around (Loosened the bolts that hold it a bit). I replaced the 'O' rings and problem solved for about 4 months, but now it's back again.
At this point mine goes off every few weeks, for a day or two, then right back on (Usually when slowing down or coming to a stop), so I think it's O.K. while driving?

Looks like we're in the same boat, I've just been ignoring it while the weather is freezing cold (which might be part of the problem?????).

[Hotsauce]

Intake gasket or EGR gasket will cause these false codes.

Its allowing unmetered air to bypass the air sensor.

John C.

[wekilled]

Thanks to all! I'll mess around with these possible solutions-maybe pickup a new O2 sensor to be safe.