Basshark7

About 6 years ago the catalytic converter on my 2000 XJ was sawn off and it was taken to the dealership for repair. I am lead to believe that the cat should be connected to the down pipe via a flange connector. However the dealership welded the new cat to the end of the down pipe with no flange. This past weekend the weld broke and the front pipe of cat fell to the ground (dirt) and dragged through the grass with Jeep in reverse. I had to pull the cat, muffler and tail pipe to get it home for repairs to not damage anything further. I intend to reuse the cat, the muffler needed replaced anyway and the tail pipe was damaged while trying to pull it out. So I guess I have a few questions.

1 Am I correct that the 2000 is supposed to have the flange connector?

2 If it is supposed to have the flange connector, can I get a new flange welded on or do I need a new down pipe?

3 Any other recommendations?

Note on terminology I don't know what to call the piece I am talking about ("down pipe"). As far as I know from the engine you have the exhaust manifold then the header which encompasses the collector. The part I am talking about is the 2.25" (I didn't measure, I'm assuming it is the same diameter as the tail pipe) pipe coming out of the collector and leading to the cat.

extrashaky

I believe that's called a crossover pipe. Yes, it originally would have had a flange at each end. You should be able to get one welded on if it's in decent shape, but it might be easier to just get one whole from a junkyard and bolt it in.

Rockfrog

The 2000 would not have a flange, it would be welded pipe, located beside the tcase on the passenger side. Cali emissions models will also have two pre-cats off the manifold.


the flange style cats ended sometime in the mid 90's

dmill89

Yes it had a flange, as stated by extrashaky you can either have a flange welded on or replace the pipe to use a stock style cat (it will probably cost as much or more to have an exhaust shop weld on a flange than it would to replace the pipe, they aren't that expensive).


However, if you want to re-use your existing cat (which I presume doesn't have a flange either) or an aftermarket "universal" cat that does not have a flange, a coupler and a couple clamps that you can get at any auto parts store will do the job.

Rockfrog

there was no flange style cats in 2000, it was a straight on welded pipe cat ... same as what he had as a replacement from the dealership. Mine was exactly the same and I just had my stock Cat removed two months ago.

dmill89

It looks like they went from non-flange back to flange mid-way through the 2000 model year so it could go either way depending on the build date. The replacement pipes/cats I'm seeing on rock-auto state that build dates after 1/21/00 used flange-style pipes and cats.


They got away from the flanges in the early 90s (93 I believe) and went back to them with the 2000 model year.


http://www.rockauto.com/catalog/x,ca...,parttype,5808

Rockfrog

looking at those parts it also coincides with the switch to Cali-emission style pre-cats for all models, which also appears to have occurred mid year 2000.

extrashaky

No. I have a mid-year 2000 (built 5/00) with EPA admissions AND flanges at each joint in the exhaust. The Jeep I bought my extra downpipe from was a 2000 with the same setup, and I've seen a couple of 2000s at the junkyard that were the same way. I don't think they stopped producing EPA emissions until the 2001 model year.

Basshark7

I will reuse the cat I have. The only thing it needs done to be back to normal is re rounding the very small flat spot in the upstream pipe end from where it smacked into the dirt. The FSM I have does not mention the flange connectors and they are not shown in any of the diagrams. My XJ does not have the pre-cats/warm-up cats. I think mine did not originally have the flanges (I don't see them any where else on the exhaust system). It sounds like I would need to check the production date to be sure.

Thank you guys

andrewmp6

Any local exhaust shop can take are for it for you.

austinjoe13

This might be the time to upgrade...

http://performance-curve.com/410225.aspx

Having the cat welded in is much better IMO, there's no gasket to blow out.

Basshark7

Everything is clamped into place. The cat will need welded back on as it leaks at that joint. When the cat was sawn off the person was so nice as to cut right at the bend where the cross pipe goes forward over the cross member.

@Austin: Is that the same length as stock? If it is I will file that away for when the cat actually dies

austinjoe13

Roughly? Idk, I had my exhaust completely redone when I had it put on.