P0171 Code

I have a constant P0171 code on my 3.4 that pops up and I am wondering if it is my MAF. For a while my air box was broken so it was exposed to the elements so it may have gone bad.

I tried to get a voltage reading from it but got nothing, the probes are hard to get along side the wires. The ohms were 5.3 at 38 degrees F, not sure if that is any good since the FSM tells you the range at -4, 68, and 140. My code reader did say I was getting .5 m/s, or whatever the MAF reads, at idle.

My truck is getting horrible gas mileage because the fuel trim is at 35% giving me only 10 mpg. Not sure if I have a vacuum leak or not, I never changed the Plenum gaskets when I put the donor motor in this truck.

I have been putting it off since it has been so damn cold out but the mileage is just getting worse and it is starting to warm up a bit to make working on it tolerable.

What are other ways you guys test the MAF or how to make sure I can get a proper voltage reading? Any thoughts at this point would be nice.

Thanks

 

For me it was the MAF, and I just replaced it altogether.

 

Try cleaning it. If that doesn't work, just replace it. Rock Auto has them for like $50 (Denso)