My son would like to put a header on his stock 2000 XJ 4.0. We live in South Florida and don't need the duel cat down tubes. I see the 1999's have a single down tube and was wondering if any one makes a single down tube header that will fit the 2000. I am on a budget so please keep that in mind on manufactures.


I was wondering what I would have to change on the wiring for the I believe the O2 sensors going from the cats to no cats.


Thanks for any help.

 

It's actually against forum rules (see #5) to discuss deleting cats from your Jeep. Even the stupid precats on the 2000 and 2001.

But even if it weren't, the computer in a CA emissions XJ would still be expecting to see data from all four of your O2 sensors to properly set the fuel mixture. You can't just delete the sensors and hope the computer figures it out. A workaround would be complicated or expensive enough that it wouldn't be worth it.

You'll be much better off just going with a header made for the 2000/2001 XJs. Your options are more limited than the earlier models, but they're not nonexistent. Here's a list of most of the headers available for your kid's Jeep:

http://www.jeepforum.com/forum/f11/a...ffered-502290/

The Banks Torque Tubes and the Rugged Ridge curly-style headers are basically the same design and sound freakin' awesome. I'm biased, though, because I'm running Banks tubes on mine and love 'em.

 

Forget I mentioned the cat deal. I hope I will be forgiven. Thanks for the great info. I would assume with installing the headers, I would have to upgrade the down tubes and cats also? found the answer to my own question.

 

No, as long as you go with a header specifically made for the 2000 XJ, you don't have to change out the cats unless there's something wrong with them. Headers for the '00/'01 XJs should bolt right in and should include bungs for the O2 sensors.

You don't really want to swap the precats if you don't have to, because they're not cheap. If you just feel like doing it anyway, Magnaflow has a free-flow set for $800. See? Now you're not thinking about that any more. There are some less expensive options out there, but none are really cheap, and I seriously doubt any of them provide a performance improvement that is worth the money.

The rear cat has a lot more options for replacement. There's a guy on here who sells free-flow spun cats for some ridiculously low number like $30. Magnaflow makes a really nice rear cat that I got for $171 from Amazon. So you have a range of possibilities.

I will warn you that after you install the header, you may have to replace your O2 sensors. As new headers break in and burn off any oil on them, they will often foul the sensors and cause the truck to throw a CEL, especially if the sensors are old. When I did mine, I immediately got a CEL but ran it for 50 miles before changing the sensors, just to make sure everything was burned off before fouling a new set. It's not a given that yours will die on you, but you should be prepared to replace them if necessary.