Topic: Catalytic converter against skid plate

[SamB]

Would anyone with a 2.5 and automatic TJ be kind enough to take a look at how high their catalytic converter is off the skid plate?

My cat is just touching the skid plate and rattling. I'm not sure how I can lift it a bit.

[jcsanders79]

Mine did that and caused issues.  It vibrated my Transmission pan bolts loose and created lots of racket.  Got my exhaust rerouted because I put an after market skid on and nothing touches even with the tight fitting skid.  Replaced the pan an gasket and it still leaked (not out of the pan though), turns out the muffler had fallen and was resting on the skid.  got that rehung and it stopped, I can only guess that the vibrations were at fault?

So no your converter or any part of the exhaust should be thouching the t-case skid. 

[jagular7]

Coming off the trans mount itself there should be a metal rod that holds the exhaust up. The is the first hanger. The next hanger is in front of the muffler, then behind the muffler, then near end of frame. The hangers is what hold the exhaust up.

[SamB]

Maybe that's my problem. I have the bracket on the tranny mount but there's no hanger between the cat the muffler. I'll have to get under and see if there's a place for a hanger.

[jcsanders79]

Maybe that's my problem. I have the bracket on the tranny mount but there's no hanger between the cat the muffler. I'll have to get under and see if there's a place for a hanger.

I don't either, mines a 97.

[jagular7]

I don't either, mines a 97.

Oops, I don't either. I mistyped as I was going from memory. I had a new cat, muffler and tailpipe installed couple years ago. If you still have the problem, see if you can twist the exhaust around. It shouldn't move much. Check the bolts off the exhaust manifold. They should be tight. The see if the hangers show any movement (shiny areas from rubbing). There should be limited amount.

Have you been wheeling? Did you back up and may have pushed the exhaust?
This has happened to a LJ that went wheeling with us. He obviously bent the tailpipe up and over the rear axle, but once on a rack, the exhaust was all fubar!!! Luckily, he was able to get someone with vast years exhaust background (my guy) and was able to bend the down pipe which holds 2 individual prechamber cats. That would have cost quite a bit.

[jcsanders79]

You can have a hanger installed anywhere on the frame cheap.  Just take it in to your muffler shop and tell them what its doing and they should be able to tuck it back in.

[SamB]

I think someone maybe replaced the cat at some point? It's a fat round one instead of a flat oval one.

Everything is bolted tight and there is less than a quarter inch of play in the whole system, it's just enough that the cat rattles against the skid sometimes.

I'm going to get one of the cheap bolt-in replacements that is thinner, that should take care of the problem.

[Jeffy]

It really depends on what year your TJ is.  Jeep went through several exhaust changes.  The major change had to do with the cat.  Also depending on the year, you're not supposed to tamper with the cat unless it's past the Extended Federal Warranty mileage or time limit.  (This is usually around 10 years)  or if the cat gets damaged.  Also, you will need to make sure the cat you install is one meant for OBDII's.  CarSound seems to be the cheapest.  Although the cheap one is the universal and not the direct-fit.

[jfrabat]

...or if the cat gets damaged...

You mean like if you "accidentally" stab the cat with a screwdriver or some other sharp object?  Or maybe if when you are using the welder under your Jeep, you "accidentally" burn a hole in the cat converter?  I have heard of those kinds of accidents happening before...

[Jeffy]

You mean like if you "accidentally" stab the cat with a screwdriver or some other sharp object?  Or maybe if when you are using the welder under your Jeep, you "accidentally" burn a hole in the cat converter?  I have heard of those kinds of accidents happening before...

Better not breath in any of the cats innards.  That stuff is highly toxic.