so my cat has been toast for awhile purrty sure thats why my exhaust manifold gasket was blown awhile back. so heres my question i was talking to a friend about needing to replace my cat and he offered me a like new converter from an H2 hummer which if i remember correctly had true duals with a cat for each side would this work for my xj? to much flow not enough flow? not legal? etc or should i just go fork out the 200 somthun bucks for the specific one for jeep.... hoping i dont get in trouble for this from CF cause im not sure 100% of the rules on this subject

 

You would need to look to see if the input and output pipe diameters are the same size. As long as you aren't discussing removal or disabling of emissions equipment (which you aren't) then you are fine.

You can get a universal that will fit the XJ for less than $100 if the one your friend offered doesn't work.

 

even if the pipe size was different couldnt i just step the pipe size up or down or does it need to be the same

 

also cant technically get a universal cat because i live here in good ol California it sucks...

 

what years your xj? in CA emissions can be a pain. if it's older then a 95 you'll be fine as long as pipe diameter are the same, post 95 OBDII as long as the downstream O2 sensor is within 6" of the OE location you should be fine. providing the cat meets Ca (not federal) standards.


EDIT: I'm assuming your XJ is a 90 off your screen name. you should be fine.

 

its a 90 renix generation as cruiser puts it the dinosaur lol.if the pipe diameter isnt the same couldnt i just step up exhaust to match?

 

think im gonna find a shop see if i can get it welded up for 30 bucks or so

 

if the cat's bigger, no problem. if it's smaller it will be a bit restrictive and may not be efficent enough for CA.

 

went and had it welded up it definitely gave it some power back...but im having another issue when it was straight piped i could rev it up and sometimes it would die i figured not enough back pressure was the problem now with the new cat i can rev it up and when it comes back down the idle drops way low like its gonna die any ides maybe the computer just needs to adjust?

 

also only does it in park or neutral not under load

 

IAC may be getting tired

 

could be its brand new but it is from autozone maybe ill try throwing the old one back in