jrm_2011

right now i have an empty cat and no muffler is it ok to run like this

djb383

NOT!

freegdr

untill you meet the right cop then it wont be lol

brutalxj

If your jeep is older then a 96 than it is not harmful to your jeep.. My 95 has been that way for years. But if your jeep is registered and sees any road use you can really get into alot of debit if you meet the wrong pig. My 95 is dedicated trail use and not even registered any longer. So what do you use it for?

Dunzready

NO!!! The 4.0 needs back pressure and that comes from the cat and muffler. There is a high likleyhood that you can warp the exahust manifold also.

OOdynamite

no pipes=no back pressure= bad MPGs, and poor performance

brutalxj

The stock manifold is plenty of back-presser. Really its more back-presser then if you run a (high flow) cat, header, and bigger cat back system. But what do I know I have only run it for years. You can try to say all you want I know this for a fact you will never change my mind. Sorry
And yes i enjoy being stubborn

xjmuddigger

yea,im the same way

brutalxj

P.S. The clapper at the end of my stack must make up the difference in back pressure LOL

djb383

Back pressure myth busting.

http://www.google.com/#hl=en&expIds=...bf06a833fc8e14

OOdynamite

I stand corrected, thank you for clearing that up.

jrm_2011

Im not running the set up for long i just need my paycheck so i can buy the stuff to fix it right.

1991Jeep_Man

lol I was sitting here wondering if you had mentioned the myths when I saw this post. Do you think the backpressure myth will ever die?

To the OP, do NOT NOT NOT NOT NOT NOT NOT
run with a gutted cat. First off, discussing anything involving removing or eliminating the primary function of the cat is against forum rules. Running without it can be against the law and result in some nice fines. As for the muffler, if you aren't worried about sound ordinances, then go ahead. But at least have a FUNCTIONING cat converter.

1991Jeep_Man

Seriously, everyone needs to not mention running cat-less. If you are saving up to replace yours, then good. You are doing the right thing. However, to those who just say they run without and don't really care, take that somewhere else. I have seen so many threads get locked because everyone decided to run their mouth on the 'benefits' of going catless. Keep it to yourself.

jrm_2011

its still working most of the insides fell out and it is under a recall for falling apart i did not remove it