Hi I have a question I have a 2015 jk I had a local muffler shop make me an exhaust system. The jk lost performance and bottom end torque even the shifting pattern of the transmission changed. Has any one had the same issue. The local shop did was a remove the pre muffler and replaced it with manga flow and removed the original muffler . If any one can give me advice I would be great full

 

Chrysler has done a good job of making the JK not like any engine mods. They even locked the PCM again so no tuners will work. In fact, to get a supercharger, RIPP sends a new ECU.

I'd put the resonator back in and see if that works.

 

Thanks ill try it