[BlackStig]

Can I Hypothetically remove the cat on a 95 XJ with out having the CEL light come on?

If i do Hypothetically remove the cat and and O2 sensor How could Bypass it so the CEL does not come on?

[lowicz96]

It illegal to remove the cat!!


But it wont throw a CEL. 95 only has 1 O2 senor and it before the cat. If you do remove it, it will backfire occasionally

[Cherokee-at-16]

Hey im trying to replace my cat and does anyone know if you can take it out without removeing the rest of the exhaust system.......Right now im just driveing with the clamps off hopeing it will start to fall off(the cat that is)its rusted on i think

[rustywrangler]

Originally Posted by Cherokee-at-16

Hey im trying to replace my cat and does anyone know if you can take it out without removeing the rest of the exhaust system.......Right now im just driveing with the clamps off hopeing it will start to fall off(the cat that is)its rusted on i think

Sawzall or hack saw will work just fine. Then just use some clamps and adapters and you are set. IF you are welding it in, alot of time it is better to replace the muffler as well due to rust.

[Cherokee-at-16]

Originally Posted by rustywrangler

Sawzall or hack saw will work just fine. Then just use some clamps and adapters and you are set. IF you are welding it in, alot of time it is better to replace the muffler as well due to rust.

What adapters???

[talentjeep]

Originally Posted by BlackStig

Can I Hypothetically remove the cat on a 95 XJ with out having the CEL light come on?

If i do Hypothetically remove the cat and and O2 sensor How could Bypass it so the CEL does not come on?

talking about cat removal can get you banned.

You need one to make air pressure right for O2 sensor anyway and you need your O2 to help your computer make the rest of the correct emissions decisions. It's not a 1965 mustang it's a Jeep and it needs it's eyes and ears!

[Solidsyko]

idk...I had my cat blow out into my muffler, went about 6 months before I could afford a new cat. During that time my highway mileage was still around 20, but my around town went down to 15ish. New cat in and my city driving is back to 17ish. Maybe it's coincidence...but the cat seemed to effect how the engine ran at least a little around town.

[leftlanetruckin]

Originally Posted by Cherokee-at-16

What adapters???

There are adapters to go from one size of tubing to another. If your exhaust is 2.5", and the cat is 2.25", there are adapters to sleeve it down making it easier to install aftermarket cats etc.

Martin

[WrenchedXJ]

Pre-96, at least here in NC is safety inspection only, but that cat converter, muffler, all that stuff is a visual inspection. Plus on non-OBD-II vehicles, there is no O2 sensor after the cats, only before, so no CEL SHOULD be thrown.

On my old Bronco 2, of course the lovely ford engineers had two cats run in series, the PO of it had chopped the muffler off and the stuffing in the rear cat(metal mesh) was blocking the exit, as a quick fix to get her running well again, I got all that stuff out, and noticed that the front cat was clogged as it would glow red. Took a hammer drill and emptied it. With this all said, this was a TEMPORARY fix and should not , e permanent. The intentions were to put a High Flow cat on, but then I found my gem of a Cherokee and traded. Typically, car engineers design the car to run with a cat, removing one can harm the vehicle in the long run, not to mention its illegal.

[wildmustard]

I live in an apparently cat-free zone. At least all research I have done has turned up no laws that prevent removing it. Initial licensing for vehicles previously registered in my jurisdiction only requires a safety check (lights, signals, brakes, wipers, etc.) We do not ever have to submit to emissions testing. My old 93 XJ came out of storage with rust holes in both cat and muffler. A DIY replacement muffler was $60. I replaced the cat with 2 feet of straight pipe, with one end expanded by the muffler guy - $5. A couple of clamps - $5 - and presto! Beautiful solution. Nice rumble. No issues. Mileage or power differences? Who knows. Lets face it, an XJ is not gas-mileage monster, and without a dyno power is subjective.

Note that US EPA and other statements about removal of cats being illegal simply do not apply in Alberta, Canada.

I do apologize for my post, and will remove it if asked. Yes, the forum rules do indicate that breaking a law is not be discussed. However, I will point out that all indications are that I have not broken any laws.

[dagr8tim]

Originally Posted by wildmustard

I live in an apparently cat-free zone. At least all research I have done has turned up no laws that prevent removing it. Initial licensing for vehicles previously registered in my jurisdiction only requires a safety check (lights, signals, brakes, wipers, etc.) We do not ever have to submit to emissions testing. My old 93 XJ came out of storage with rust holes in both cat and muffler. A DIY replacement muffler was $60. I replaced the cat with a 2 feet of straight pipe, with one end expanded by the muffler guy - $5. A couple of clamps - $5 - and presto! Beautiful solution. Nice rumble. No issues. Mileage or power differences? Who knows. Lets face it, an XJ is not gas-mileage monster, and without a dyno power is subjective.

Top of page #2:
http://www.epa.gov/compliance/enforc...hsysrepair.pdf

[Pats94]

I've read that before to follow the letter of the law installing high flow cats unless certified as direct replacements are illegal. Air intake and muffler enhancements violates epa certified noise levels.
You all in violation so park them.

[dmill89]

Originally Posted by dagr8tim

Top of page #2:
http://www.epa.gov/compliance/enforc...hsysrepair.pdf

^ wildmustard is in Canada, the EPA being a US gov. agency has no jurisdiction there so this doesn't apply to him. I'm not sure what if any restrictions exist in Canada as far as modifying or removing the cat.

[Purcell69]

With regard to the OP's question, you can replace the two wire O2 sensor with a heated four wire sensor, connected to keyed 12v power, to help tell the computer what to do. From the other posts, it seems that it will not throw a CEL either way. I have a 1995 parts XJ that I pulled the exhaust off of and I have driven it around my property without getting a CEL, but then it was only run for a few minutes.

-Joe

[mschi772]

Regardless of your local laws, discussing topics like this are not allowed here because the JF does not want to facilitate dispersal of any info of this type to people who do have laws against it (that's my interpretation of one of the reasons for the forum rule anyway).

Even though you don't have any laws prohibiting it, you gain nothing by removing the cat (cats aren't restrictive and have an utterly negligible effect on performance). Cats last a long time and are relatively cheap for their lifespan, so if you have a cat problem, fix it. O2 sensors do more for your Jeep than just monitoring the cat, so it's in your and your Jeep's best interest to maintain the O2 sensors as well. By removing the cat, you only serve to pollute our air.