• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Gutted Cat

C

Cherokeekid88

NAXJA Forum User
Location
North Carolina
So i think my cat is gonna be going out pretty soon. I just replaced the one on the GF's XJ. Was wondering anyone have any experience with gutted cats??? A buddy of mine took his off and took a broom stick and pushed all the crap out of it and welded it back up. Mine is an 88 so it doesnt have to pass Emiss. Any drawbacks to having a gutted cat? Im also running a FM40 muffler and im thinking it will sound pretty sick with a gutted cat.
 
I took mine off and ran a peice of rebar tru it.. simple as that.
Lil more HP, maybe 1-2 MPG

Less resistance coming out of the engine the better
 
If you gut your cat, it will probably die. You can fletch your arrows or stitch wounds though..


Back to our century, some shops will make you a "test pipe", to help you "test if your cat is affecting performance" - but its illegal so you have to be careful how you ask. :)
 
Yeah, thats a no-no for shops.. its a do at home job.
 
cal said:
If you gut your cat, it will probably die. You can fletch your arrows or stitch wounds though..


. :)
Click to expand...

makes great tennis racket strings and fishin leaders too
 
HAHA. Well i want a little more umph out of my exhaust without putting out alot of money. Ive heard that jeeps with FM40 and gutted cat sounds awesome and ive heard it sounds raspy and it pops. Hi flow cats are pretty expensive, any ideas?
 
Run some lead subsitute in your gas and it'll burn the cat out..might be a il easier on ya.
 
Take it off and hammer the crap out of it. Typically they're installed just aft of the mount at the tranny crossmember. So you can unbolt it to gain access to one side of the cat, and using rebar/pipe/pry bar smash everything out of it. Then you bolt it back up and fire the engine up and watch the cloud of metal particles come out of your tailpipe.
 
I think I paid $60 for my hi-flow cat. Its my second one. I ran a gutted cat for about a year, i think the jeep sounds better with a hi-flow (empty it was too loud).

All of that is with a FM 40.
 
wouldn't he lose some performance because the o2 sensors would go crazy? correct me if i'm wrong.
 
cal said:
I think I paid $60 for my hi-flow cat. Its my second one. I ran a gutted cat for about a year, i think the jeep sounds better with a hi-flow (empty it was too loud).

All of that is with a FM 40.
Click to expand...


Where did you get you hi flow cat at for 60 bucks?!
 
lancey3 said:
wouldn't he lose some performance because the o2 sensors would go crazy? correct me if i'm wrong.
Click to expand...


Depends on the year, and there are some "liar" sensors that plug right in to fix that.
 
Cherokeekid88 said:
Where did you get you hi flow cat at for 60 bucks?!
Click to expand...

Ebay, dynomax. it was a "damaged packing" one - the corner of the box was crushed a little. The other I got was also ebay, an off brand that performed just as well. That one was crushed on the rocks, so I gutted it on the trail, and bought the new one when it was smog time again.
 
I've heard one with a gutted cat and a crappy replacement exhaust, sounds decent at idle, but I think what minimal advantage for that old well used motor was lost with that crap muffler it has on it.
 
cal said:
I think I paid $60 for my hi-flow cat. Its my second one. I ran a gutted cat for about a year, i think the jeep sounds better with a hi-flow (empty it was too loud).

All of that is with a FM 40.
Click to expand...

What he said. They're cheap if shop around, try www.performance-curve.com

For no more than $60.00, why not run one? A modern cat in good condition will have alomst no effect on power or economy on a normal (ie non race car) engine.
 
I gutted mine on my 93 temporarily. I hit a flooded road going too fast and the exhaust separated at the cat. The cat hit the pavement. cracking it and was underwater being force-fed water and crap.

With the FM 40 it sounded a bit tinny and when doing a high RPM shift it would shoot blue flames from the tailpipe.

I got the High flow e-bay model on my latest XJ, I got a universal mount and had the shop weld a bung onto the backside for the after cat sensor.

Oh and I replaced all of the pipe from the collector back with 3" and went with a 3" high flow cat. Now it sounds SWEET, but I can't hear anything but exhaust resonance while cruising down the highway, and I can't idle through a parking lot without setting off someones car alarm.
 
I'm with you goodburbon, I'm 2.5" from the header out (borla stuff) and i can't hold a conversation at highway speeds its so loud.
 
get a hi-flow cat (magnaflow ones are pretty cheap) and a Twister race "muffler" :)

Talk about a unique and bad-ass sound. Only $45 for the muffler too, and its a 5" tube style muffler...
 
You must log in or register to reply here.

Similar threads

X
2001 xj high-flow cat recomendations?
Replies
2
Views
3K
maxbraketorque
M
M
2000 cherokee chk eng light
Replies
11
Views
1K
XJI6191
X
X
2.5 exhaust Questions
Replies
5
Views
5K
75SV1
7
X
Help me my Obi Wan Kenobi's
2 3
Replies
47
Views
13K
75SV1
7
W
99 sport - Holes in exhaust resonator...exhaust size?
Replies
9
Views
1K
Woodswanderer
W
Back
Top