I happen to live in a wonderful county where there is no emissions testing. It is, therefore, common for people to straight pipe their rigs of all kinds here. Also, rust is only a rumor of the coastal areas of this great country and does not exist in this pristine location. So the question, and title of this thread is: Should I straight pipe my 07 JK? I have heard rumors that removing the cats and shutting of the 02 sensors can seriously mess with the tuning and destroy engine performance. I don't want that. I realize I should actually talk to one of the shops here that straight pipe vehicles but I wanted to see if anyone in this community had some sage advice or warnings or any general exhaust wisdom to share. I don't want to be overly loud. But I do want a meaty grumble (yes I know I should put a hemi or 350 or a I6 cummins or anything better than the 3.8 to get what I want) and, most importantly, the added power and efficiency that allowing and engine to breath gives you. So who has stories of tragedies or any words of encouragement for this undertaking. Please note, I do have to make many elevation changes of over 1000' during my adventures.

 

Modern cats don't affect performance so if you are looking for more noise just do a muffler delete, that's where your back pressure is coming from but don't be surprised if the neighbors get upset

 

These 3.8's do better with some back pressure. If you straight pipe it, you will lose what little low end torque these motors have.

 

Ask Maertz about it. He did it. Currently looking for ways to quiet it down. Jeeps suck with loud exhaust. Too much of the noise enters the cabin.

 

I blew the muffler off on a trail and I can say it sounds worse then a civic with a fart can.

 

But a dynomax rock crawler or you can buy the dynomax ultra flow from me 😏😁

 

people who make their vehicles stupid loud are just crying for attention. if you really want that just paint it barbie pink. you will get the attention and it wont bother others. you wont gain anything on an na engine with straight pipes infact you will probably lose some low end.

 

Here ya go.

 

I had cut a magnaflow into the pipe between the frame rails then had a local muffler shop bend me a new tailpipe. Total cost was around 150 bucks, it's all stainless and has a nice sound that doesn't attract attention.

 

I don't know how removing the cats will affect performance (very little from what I understand) but you certainly don't want to remove the o2 sensors. The engine computer uses the readings from those to control the fuel mixture. It'll still run without them (although with the light on the dash on all the time) because there's a default tune the engine uses until the o2 sensors warm up but if you remove them then you're using that default all the time. This isn't ideal, especially with the elevation changes you mentioned.