Removing the Cat
 

I have a 1998 xj 4.0

I'm thinking of getting a straight pipe and cutting out the box and catalytic convertor.

The cat has a sensor in it, if I had a straight through pipe what should I do with this sensor? Anyone done this mod?

Yes take out the cat. Weld in a sensor bung about the same position as is on the cat. Install the straight pipe. Install a defouler/spacer. Install the downstream o2 sensor into the spacer. Straight pipe, no cat, no CEL.

defouler/spacer?

Where do you put this? Are there 2 sensors on the exhaust?

Ebay item number: 301853266499

I'll snap a pic of the pipe I made.

I thought it was against forum policy to discuss removing the cat?

Sorry didn't realise.

It's now rattling like it's going to fall off anyway. The truck came with a new one but it's 110% not for the Cherokee, different shape, no hole for a sensor. No idea what it's for. Might try and make a hole for the sensor and wedge it on somehow. Angle grinder and clamps

Last I update I read it was now an open topic.

It's probably for a non-injected vehicle of some kind. Aftermarket anyway. I had a 89 Chevy truck 350 with a throttle body injection unit on it that only had 1 sensor in the left manifold. The PO had put dual exhaust on it with 2 little cats for the 4 liter V6 on it that didn't have any holes for sensors.

My wife bought a Dodge Caravan and somebody had stripped out the downstream sensor and welded a new one in! Of course that went bad and instead of replacing the whole thing, i just cut the pipe and bought a coupling, welded a bung into it for the sensor, and mounted it with 2 muffler clamps.

The thing about talking about removing the converter was mentioned by the moderators but doesn't seem to be enforced. I just stuck that in there as a barb. I was approached by an administrator about becoming a moderator and I told him I've got enough to do just answering questions!