Ever since i got my cat back exhaust system, i have gotten less power after 3800 rpm mark. I would feel the acceleration before 3800 rpm and after it takes time to get to 6 or 7..... when i bought the car, it had no problem going to 6 or 7..... its struggling right now... any ideas? i also reset the ECU just to see if there is a problem with temp sensor b/c of the cai.... but nope that wasnt it....
can it be oxygen sensor?
help! thanks

 

O2 sensor doesn't affect WOT. Maybe have the dealership perform the reprogram that typically is associated with a new MAF.

 

Why would you reset ECU? Was your CEL on when this started happening? Not enough info here to help you out buddy.

 

Exhaust leak since catback install, check for leaks.