LTFT's +20
 

I tuned my engine about a week or so ago and everything was running great.

Just went to the dyno this past weekend to try out a 50 shot.

I ran pig rich on the dyno without the N20. AFR was 10:1 :eek2:

After checking EFI, my B1S1 was +20. B2S1 was locked at zero. LTFT's were negative but when I go WOT, they hit zero for a moment then +20.

Any idea what could cause this??

Sounds like a vaccum leak

You mean air getting into the exhuast??

Yes. I meant to add exhaust leak also. Since in closed loop the O2's directly affect LTRIMS if your O2's detect excesive air on that bank it will contiune to make the LTRIMS go positive. Eventually it will set a code.

Normal part throttle driving, all fuel cells are negative. Nothing extreme except for decel which is the SC.

I will be on the freeway cruising about 70 mph. LTFT's are -1 to -3.
As soon as I go WOT, they wil jump to zero, then B1S1 will shoot up to +20.

I'll check the exhaust on the driver side and make sure there is no air getting in. Its just weird that part-throttle is fine.

Sounds odd. WOT shouldnt be using o2 feedback. Is you COT turned off (Catylitic OverTemp)

Yes COT is turned off. Its is wierd, everything was fine a week ago.
And this is happening only on bank one. I am going to switch sides on the o2 sensors and see if it moves to bank 2.

I still don't know what caused it, but I cleared the LTFT's and so far it is working fine. :confused:

When I had my headers open, I seen LTFTs of +25 and +50 sometimes...yikes.

Better take the blower off Ed ! :D

Hehe, just kidding. Look for air leaks (vac/exhaust) on the side reading lean.

Maybe it takes WOT pressure for it to leak ?

Let me know if you need a hand.

Rob (Bad30th)

Thanks Rob, so far so good. I'll be ready for the track. :)