I used to have a 40 series two chamber Flowmaster that was dumped with no cat on my 4 bander toyota. Made my truck sound like a loud *** V8. I loved it but it became a pain when I wanted to surprise the girlfriend or come home late to my dads. Trying to coast down a street and then still get into my spot in the drive way was a challenge. But I have a cherry on my Bronco and I plan on getting one for the GC

 

if you have a 96+ wouldnt hollowing out the cat screw up o2 sensors and back pressure? why do it? i would think it would i just make your jeep run and smell like **** haha

 

I have a 40 series flowmaster on my Jeep and it's loud, girlfriend says she can hear me coming. I want it louder though, but I'm not sure if the glasspack would make it louder or not. My friend who has one on his is not as loud as me I don't think, but I could always gut the cat like you guys said...opinions?

 

Well, I broke the o2 sensor when I pulled it. Yeah, the light is on for now. But, I wanted to see how it would read when I replace it. I was planning on putting a high flow in but if the new sensor reads ok, I thought why waste the money. I like to try it 1st. With the cat hollowed and the cherrybomb, I am getting about 3-4 more mpg's. The cold air intake might have had something to do with that but the mid to top end is a lot better now. I had a buddy that did that to his 97 xj and ran it for years and never had a problem. Knock on wood.

 

When I got my 95 XJ the combs in the Cat were loose and moving around in the Cat making it bog down at WOT, so when I put the new Cat-back on I did the ol pry bar and hammer to the cat. With the header,hollow cat and Cat-back she's LOUD when I hammer down, I love it. Scared more then one person out of my way when getting on the highway. ported the intake manifold a bit too and along with bigger throttle body helps her breathe in a little more air too.
Sounds really good when plowing in the winter too.

Thinking of doing it to my 95 ZJ too, also a 4.0.

 

How much it costs?

 

My cherry bomb isnt as loud as i would like is there anything i can do?

 

can we get a small write up on the hollowing out of the cat im one of those that needs instructuons on the simpliest of projects
would be greatly appreciated!!

 

x2 a write up would make it look like its something technical besides beating the crap outta ur muffler.

 

Yeah, that's my problem. However, running with the volunteer fire department most of the cops just wave at you. I plan on getting a "second" exhaust for emissions time since they're only once a year. It's a lot of work though, oh well.

 

i bought my ZJ with the cat already removed and a C/B glasspack welded in, it's not that loud. My old XJ got that and it was loud, my current 94 Dakota has no cat and glasspack, the tailpipe comes out infront of the rear tire....it's waay loud.