09ORANGEJEEP

Anyone encounter major loss of performance after installing Cat Back system? I installed one from Dynomax w/dual exhaust. Rather than gain about 15 HP as advertised, I lost a great deal of power. Very slugish and performs like a weak 4 cyl. Thought it was me but wife also noticed after driving to work. I am stumped. The jeep has cold Air intake, perf throttle (bored out to 65MM) and Superchips perf chip with no other mods. previous perf was great and quick off the start and super mid range get up and go with chip set at 91 or 92 Octane. Thought catback would even add more get up and go. No dice!!!!

Dylanjam77

Welcome to finally posting on the forum, I see you have been a member since 1/09... Hard to say for sure but there are many post's by folks who have gone with a dual port/dual exhaust if you will cat back that have been VERY unsatisfied with the results. I think you will find if you do a search of cat back systems that a single port exhaust works best with our 3.8L's.

I would also check the connections... did you weld or use clamps? Back pressure loss would be a major issue with loose clamps. Go back and check all the connections if that is the case.

09ORANGEJEEP

Thks Dylanjam77. I checked the connections (clamps) and found all Ok. I was already thinking only fix would be to go back to stock sytem rather than try a single port and waste more money. The current cat back was $468.00 from Sumitt Racing and they say no return even though I had it installed only one week - bummer! I see you also have sunburst orange jeep - great.

Adam3612

The single exit system is the only way to go, the dual setups decrease your backpressure way too much therefore your loss in power. Personally I like MBRP's systems, nice throaty growl, no drone and no loss in power (small gain, or so the butt dyno says). Dynomax do make a nice product as well, i've driven plenty of vehicles with one of their systems installed and they are nice, just stay away from dual exits.

IcyFridge

Dual exhausts do that sometimes. Give it some time for the ECU to relearn? Try flashing back to stock and drive around a bit and then flash back to whatever tune you are running. The SC tune is prolly already "learned" and you added a catback to the mix and it has not adjusted accordingly.

I always reset my ECU when changing intake or exhaust.

RevyJKU08

Bingo...also, backpressure is reduce if you went with a much larger diameter pipe.

Doc_D

You have a lot of mods that the superchips doesn't expect. You could be running lean and experiencing knock. This will cause the ECU to retard timing and performance will suffer considerably.

I'd give this a shot. Fill up with 93 octane. Flash back to the 87 tune. If it runs good, then the superchips flash is probably a little too lean for the modifications you are running. If that's the case I'd give them a call and ask them about it.

I've noticed a lot of people lately complaing about pinging and loss of performance when running thigns like cold air intakes and exhausts with the super chips tune. Hopefully eventually they'll have the programmer ask you if you are running these mods and enrichen the fuel maps a little bit if you are.