98jeepster

how can i remove the cat and keep the check engine light from coming on.

Modestmike

Doesn't anyone read the stickies?

AeroSynch

To save you from future flaming, removing the cat is illegal and is frowned upon in this forum.

That, and you will get crappy MPGs etc.

Unless removing it to instantly replace it with a new one?

fishtaconc

Only people that already know better.

Modestmike

Ahhhhh.... I see that he just joined and it's his first post. Fair enough. Now you know friend.

1991Jeep_Man

First off, it isn't possible. The post-cat sensor will detect the untreated exhaust and throw a code. Removal of the sensor will throw a code.

Second, there should be no reason why you would do this. Even if it was for replacement, you would put the cat on before driving. If your cat is trashed and needs REPLACED, then there's a vendor on the forum with high flow cats for about $40 or so. Otherwise, leave your cat on and alone. It's the law and wanted by forum admin.

trans_am7935

this thread will probably be locked soon enough, but you really need to read the rules. not just illegal, no reason for it at all. you do not have a race car. the cat is there for a reason. please leave it alone.

djb383

Don't remove the sensor(s).

elalr

i recently joined and i recently bought 2 1990s. one 2 door and one 4 door. both have the cat gone. neither have a light on. i guess i thought it was common. i am ignorant of the full purpose of them. i have always ran diesels and older gas engines none of which have cats. was there a sensor past the cat? one runs really well but gets poor mileage (14 mpg hwy) it also is running oversized tires and a rachet locker in the rear. the other runs rough at low rpms but runs out smooth on the hwy. it gets about 16 mpg hwy at 70 mph. im here to learn! thanks for all the help you all give!

89Laredo

90 is a "renix" Theyre pre-obd, no CEL
They have only one oxygen sensor, on the downpipe.
I usually make a big multi paragraph post about renix, but I dont feel like it right now. Maybe Ill pm it to you later.

1991Jeep_Man

Lol, funniest thing I've heard all day.

elalr

im searchin all i can. there is just so much info its overwhelming. sometimes hard to wade through it. im unclear on a lot of the lingo and terms also. again thanks for helpin!

98jeepster

Hey i'm realy sorry I didn't know it was so frowned upon.the city I live doesn't have emissions so we don't worry about it but its not that I wanted to take it its actuall working just fine but I want it to be a little louder and I guess ill just leave it alone and get a high flow when I can but thank you for the info. And I apolgize to everyone that I offended on that though I have supra and well im just used to my cars not having any back pressure because it boosted and its a topend car I don't need back pressure but ill leave it on there and just put a muffler on it.

OOdynamite

It's ok, just know that the mods will most likely close the thread. If you want it to be louder go to the venders section. There is a vender selling flowmaster mufflers with new pipes for about 100 dollars which is a very good price, check it out.

Heres the link:

https://www.cherokeeforum.com/f10/ne...st-kits-45131/

MountPXJ

Ok so I have a similar situation. My converter is shot and I ordered a replacement along with a new catback. What is the best way to take the cat off of the frontpipe so that re-installation will go smothly?

The new pieces are clamp on so I will not be welding.

1998 XJ Sport