1996 4.0 and the engine has almost no power o it. when i go up a hill or something i can only do 25 mph. it isnt quite as bad when driving on a flat but the engine just revs loud and all the exhaust just trys to come out from the front some where cause it dont seem to come from the exhaust pipe its self.. im thinking it is clogged at the cat cause it has had a loud rattleing noise from in side of it for while when i start it and then when i stop but it dont do it while i have the gas in... what do u think and what should i do?

 

Sounds like a clogged cat, and you can replace it with an after market piece, but it needs to be replaced, and not removed. You pick up a new cat fairly cheap, and if you can weld, you can install it with ease. HTH!!

 

i put cats on all day every day. it sound like it is clogged. yes you can buy a universal cat and weld it in. DO NOT go cheap. the 25 dollar autozone cats are junk. most of the time the are only built to the min. specs and alot of times they aret even enough to turn off your check engine light.

 

I just picked up a cat from the junkyard for my 96. It was 25 bucks, but be sure to make sure it's not cracked or anything. Bolted right on. I had a straight pipe welded where the cat was and the CEL was on since there was no O2 sensor. So basically don't just put in a straight pipe.

 

I bought my cat from Summit Racing for $114 for Magnaflow and sold my old one to the jy for $35. So it worked out to be $79 . Not bad.