Just a note before my question, I know that it is illegal to drive a vehicle registered on road without a cat, and have working converters and my street vehicles.

But my jeep may become strictly an off road toy and I was wondering what the best thing to run would be. It is already straight pipes to a cat and then cut off by the rear passenger tire.
Do jeep engines like some back pressure? Or can I run it straight pipes all the way?

 

It is illegal to remove the cat, period. It is also frowned upon talking about it here at all, and against forum rules. There is a sticky at the top of the page with CC laws, and here is a link from a different page that states the EPA laws on the subject:
http://publicaccess.supportportal.co...-Is-that-legal

 

Op, keep the cat but yes, run a muffler or atleast a glasspack if you love the straight pipe sound.

 

The other thing to remember is BLM and NFS will require you to have some kind of muffler or spark arrestor, to prevent fires from engine backfire/exhaust...get caught without it and you could be facing some heavy fines

 

It is illegal to remove the cat on a road going vehicle. Off road use vehicles such as tractors and race cars do not require them. Such as when you look for test pipes on cars they say off road use only. I drive a Miata know about rules the EPA has for non road use vehicles as I have been interested in making it into a club racer and done plenty of research. I am simply asking about if Cherokee 4.0 engines like back pressure in the exhaust or not.

 

I should have started this out saying "Hypothetically if I were to remove the cat on my jeep would it need backpressure to run fine?"

 

Jeeps like back pressure. Not sure why the masses thing canning a cat is good. Keep it or get a highflow.

 

Yeah, I would honestly just leave the stock cat-in place. It should provide sufficient backpressure on its own, without a muffler. You wont really gain much power if you remove it, and you could very well ruin the torque curve.

 

High flow cats are a joke, the only difference is the weld on the inside is ground smooth. I dont think that would benefit you unless you had a blower or something like that.