07’ Vibe with infamous P0171

[BethanyWashingtonCo]

My girlfriend’s vibe has thrown out codes on an off for about two years.

Before I started helping her she had a gas cap replaced, then the MAF, O2 sensor replaced.

Now we have to get an emissions test done, and I’ve been trying to pin point the cause.

At first we did the intake manifold and valve cover gasket, then we did the pcv valve, and at this point the light has gone away.

So, I wanted to confirm the fix and I used a scanner- long term fuel trim is down from 30% to 15%and short term is between 1-5% down from 20%.

So things look good, but the trim is still high, and the MAF is reporting 1.65 g/s of air.

The g/s goes up at 2500rpm and the fuel trip goes down to about 9% long term.

It seems like I might still be dealing with pirate air, or maybe I should try another new MAF. Our next project is the fuel pump assembly and put some fuel injector cleaner in the tank. But, given my understanding of fuel trim levels I don’t think we have a fuel delivery issue.

Any suggestions are appreciated.