Hi, I removed my rear muffler and installed an off set straight through muffler before the diff. I have a 3.8 auto and now it feels like I have lost power/torque and also it feels like the shifting on the auto feels like it's a bit off now. Am I imagining all this or has the exhaust mod affected my performance?

 

In theory, yes. Increasing air flow decreases back pressure which decreases torque- in theory. I don't have any set percentages you may have lost but that's the theory behind it.

 

have you messed with the cats or is the exhaust just a cat back? If its just a cat back there should be very little performance loss if any. Normally you dont really lose power you just move the power band arround a little . when you open up the exhaust you lose some low end and gain some on the high end ( NA vehicles )

 

Thanks for the feed back, yes it does feel like I have lost a bit of bottom end and the top end a bit more free but wouldn't say has any more power. It is only a cat back system so have not touched the cats or cross over pipes. I definitely don't like how the jeep feels now so I am going to try a different muffler that will provide a bit of back pressure, hopefully this will keep it feeling more like stock. My normal driving tends to keep the rpm's in the green zone (under 3k) and now it feels like it has nothing in that powerband.