I had my check engine light come on yesterday, and since I work at a car dealership in the city, I had the guys in service hook up a code reader to tell me exactly what's going on. Turns out I need a new catalytic converter. Or <i>might</i> need a new catalytic converter.

My buddy told me I may as well cut it off and be done with it since emission laws here in Oklahoma are non-existent.

Now go easy on me, I'm not very mechanically-inclined.
Should I just hack it off and not worry about it?

 

NEVER REMOVE THE CAT. It may just be a rear O2 sensor. If that sensor goes bad the computer thinks it's the cat that is bad since that is what that O2 sensor monitors. You can check if the cat is dead or not by using a thermal temp gun. It should be 100 degrees hotter (or more) behind the cat than in front of the cat. Just check the exhaust pipe right in front of the cat and right behind.

Max

 

FYI the o2 affiliated with the catalytic converter does nothing to affect how the engine runs. it is simply a tattletale.

 

new catalytic converters are good. they serve a purpose and most flow well now. it is also illegal to remove it from a vehicle that came with one. you can find replacement ones for pretty cheap.

google, "xj high flow cat" or "xj thunderbolt cat" i have one on my 98 and it throws no codes and was pretty cheap. if you are OBDII you will want part number 425250; if OBDI, 410250.

 

Update: the code it threw is P0420. Does that provide any more clarification on the issue?

 

http://www.obd-codes.com/p0420

Scroll down to where it says "causes", and start diagnosing...more than likely a bad sensor or wiring...but, you won't know until you do some noggin' pokin'

 

P0420 is just a generic "catalytic converter below efficiency" code. The ECU thinks that your cat is no longer functioning as it should, based on O2 sensor readings of hydrocarbons, CO, and NOX before and after the cat. Sometimes it really is the cat, especially if your burning alot of oil or running rich for a long time. They sometimes clog up, but if you haven't noticed it running rough or stumbling that's probably not the issue. Usually it's just a fried O2 sensor. They generally only last about ~100k miles sometimes more depending on brand. Denso seems to last longer.

How many miles are on your XJ?

 

A factory cat can be scrapped for $30+. A quality cat to replace it can be bought from Performance-Curve.com for roughly $70. If your cat is indeed bad, replace it, don't delete it. Make sure it isn't just the O2 sensor itself that has gone bad first, though.

 

I've got 215k on it right now.

 

I agree on replacing it and not deleting it, emissions testing could possibly come to your county and without a cat you'd be screwed lol. I was about to delete mine but I heard emissions was coming so I put the cut-off wheel away

 

Removing Catalytic Converter conversations are bad topics here since it is an illegal activity regardless of local laws, they are federally mandated......

 

Even if you don't have smog testing if a cop looks under your jeep and sees the cat is missing can impound your jeep on the spot.For a high flow one http://performance-curve.com/ has them,If your on a tight budget call around all the small exhaust shops they are cheaper.