Stock 2006 GTO-Very lean in OL-Help!

[drivefastgto]

I'm about to lose my mind on this...Stock 2006 GTO, LS2, NO tuning done besides removing CAGS, speed limiter, etc...

When in closed loop, AFR is about 14.7, but when I put it into open loop, the AFR goes to about 16:1, cold or hot engine. If I set commanded AFR to 13:1 it runs at around 15:1. I have checked the MAP, TPS, ECT, etc. against my old logs and all that seems to read normally. Fuel pressure reads about 70 PSI (!). Also, LTFTs are 8 to 12 positive.

What I find really odd is that I drove around for a while in OL 3 months ago, and it held commanded AFR just fine. Thanks in advance for any advice.

[svede1212]

well from what i know if you are lean all of the time in OL then your VE table isn't right (too low of values). you really need a wideband to tune for running in OL.

[drivefastgto]

I am indeed running a wideband...That's how i know what my AFR is.

I just find it really strange that the stock VE table on a TOTALLY stock car would be that far off, especially since 2 months ago the commanded and measured AFRs in OL were not very far off at all.

[drivefastgto]

Also, for what it's worth, IAT's are reading near ambient...

[EC_Tune]

How different are the ambient temperatures from when you tuned it last and now? If >30 F then I would suspect that the temperature compensation is not exactly ideal. Not too unusual BTW.