jstrabley

The cat converter has rattled on my 98 XJ since I bought it about a year and a half ago. Now, when I give it some gas, it's unresponsive for a bit and kind of sputters out before taking off. I'm also getting a "chugging" like sound when accelerating. I'm assuming that the cat converter is clogged.

My questions are:

1. Does it sound like my assumption on the bad cat converter is correct?
2. How do I go about replacing it cheaply? Can I cut the old one out with a hack saw and simply slide the new on into the exhaust pipe and fasten with exhaust clamps? That sounds too easy and I'm sure I'm missing something, but can't find a write up on it.

Please keep in mind that I do not want my CEL to be on and would need to be able to pass emissions.

brutalxj

I would guess you need a tune up way before the cat is clogged. And the rattling is just the heat shield on the out side of the cat or on the under-body of your XJ. But if in fact you are right that is one way to change out your cat. If I were you I would use band clamps and not those crappy u-bolt ones that always leak and rust so fast they are not re useable. Welding it in is still the best way. Oh if your cel isn't on now then it isn't you cat. I would also take the time to clean your 02 sensors now as well as they can cause the issues your describing. That only costs a half a can of brake clean and should be done every tune up unless you hate money?

djb383

The cat on our '98 was a factory "slip fit" at both ends and clamped. Depends on how rusty things are as to how easily it "un-slips". Ours popped right off at both ends.

brutalxj

Sounds like yours was already replaced I have been under at least 20 97-99 and none of them were like that.

hico

X2!!!
I would also take the time to clean your 02 sensors now as well as they can cause the issues your describing. That only costs a half a can of brake clean and should be done every tune up unless you hate money?

djb383

Looks original to me, but maybe not. Muff and cat had the Chrysler PentaStar on the cases.

brutalxj

First time I have seen a set up like that come stock. Normally see it all one welded piece or with a bolt flange thing.

UsmclovesXJ

On my the cat is welded to the down pipe and clamped from there on.

djb383

I believe the '98 FSM shows it's all clamped, except for the muff/tailpipe, they are welded.