I replaced my failing S5 TPS with a TPS from an S5 NA, adjusted it into spec while the engine was hot, and it fixed my surging at acceleration. However, instead of the car going into closed loop at 14.5-15 AFR at cruising speeds, it now hovers around 12-13. So I'm not sure if it is going into closed loop or not. I figured if it wasn't I'd get a CEL, because it would be using default fuel maps, which are richer than normal.

Any suggestions?

 

Replace the O2 sensor. A universal Bosch 1 wire is cheap

 

I just replaced the O2 a few weeks ago when I installed the exhaust. And the old O2 sensor I had in there was no good, and it was causing a CEL. Wouldn't the new one cause a CEL if it was no good as well?

 

The O2 sensor I put in the car was used, but only slightly.

 

Crap, I'm back to square one on this. See this post https://www.rx7club.com/showthread.p...ust+lean+issue