So this past weekend I was at DGRR 2K7 beating the snot out of the 7, with no issues, she ran fine the whole time.



So I stayed last night with my in-laws in Chattanooga, and this morning when I started off home, she was acting strange.



1) The A/F Gauge is reading closed loop when it shouldn't.

2) Under light throttle it reads fine, then it quickly shoots to lean and goes blank when you accelerate harder.

3) Under light acceleration at low RPM's she sputters and bucks if you push hard.



I am thinking the O2 sensor is toasted, but didn't think it would effect any of this. The car is emissions free, no cats, and I just put an FD pump in it last week. No way its running lean (ask anyone who is behind me!)



The O2 is a universal Bosch that I put in when the motor was swapped in (rebuilt).



Or is it just maybe a random vacuum leak?



PS- No check engine light. Mods in Sig.

id look for something the fell off? o2 is possible but wouldnt be my 1st choice

Well I don't think anything fell off. I looked over the entire engine bay and its all good. I think I am going to put in a new O2 sensor and then spray carb cleaner around to check for vacuum leaks.



No other ideas??

Im having a simular problem with mine, ive changed the o2, checked and rechecked for vacume leaks also regrounded the car, set the throtle, and finaly put new secondary injecters in and still nothing seems to change. so hopefully that will get you cought up on what i dont think it is. next im going to go get a j-yard ecu and see if that helps.

check it for codes?

I don't think I want to check for codes. Having no emissions I can only imagine how many are lurking in there!!!