Okay. So I have been at it with this car for the better part of a year.
ITs a turbo b18c on s300. Tuned, it made 471. For like 4 passes.

Chased alot of issues of it not making boost to VSS. Re-pinned to the ECU now it's reading. But now the car only allows 1 pass. It'll make full boost for 1 pass. Then the car will fall on its face. If I do nothing, let the car sit over night, I'll get another full pass.

What would make my car do this?

Also problem two seems to be a random stalling issue. Looking at my AFRs (before I lost my sensor) it looked like the car was getting really lean randomly at idle after driving for awhile.

Thanks.

 

I should note, by fall on its face, it'll hit 11lbs and then almost cut, and then try to build again.

Electrical and mechanical timing are dead on.

 

You will need to elaborate more. Without being specific, i suggest taking it back to the tuner. If it was something mechanical, you would not get the one full pull. It woupd act the same everytime.

 

Sounds like your tune needs to be gone through. Log some pulls, some normal driving, and some idling to capture when the issues are happening, then comb through the data to see what the cause is. If you don't feel comfortable doing it, take it to a competent tuner.

The lean stall at idle could be a number of things - running in closed loop with bad "rate of change" settings, bad compensations being set up, etc.