I've owned my 8 for a few months now and when I first got it the car felt very fast all the way to redline. Recently I felt some power loss and figured it was just in my head and I was getting used to the power. My 8 finally threw a CEL and it was the catalytic converter. Instead of paying $600-1k for a new cat I purchased an AP mid pipe instead. After installing I've noticed improved gas mileage, but it doesn't seem like it pulls as hard all the way to red line anymore.

I've done some research and was wondering since I installed the new mid pipe if the ECU needed time to re-adjust the fuel trims and maybe the power will come back? Any help you guys can provide would be great! Thanks

04 6spd GT
SR Motorsports Intake and Pulleys
AP Mid pipe

 

When my cat failed, my engine never quite felt right ever again. I didn't get most of that back until I also replaced the front O2 sensor, as it became cooked from the cat heat. I'm also convinced that the heat buildup slightly warped a rotor housing, allowing a very slow coolant/oil leak into the engine, leading to my engine replacement nearly 40,000 miles later (consistent but brief plume of dense smoke after letting the car sit overnight, problem disappeared after engine replacement)

 

Thank you for the answer! I dont have a CEL or anything, is there a way to tell if the front o2 sensor is dead/going bad too? Also 2 days before i switched my cat for a mid pipe the CEL went off, one of the guys here at work told me the computer reset after so many starts in case it made an error. Is this true?

Thanks again for all the help!