97 ZJ Muffler question

You sure the cat is still good? Bummer to replace everything else then have to go back and fight the battle again to replace the cat. I'm trying to remember for sure, but I think the pipe fits over the outlet of the cat. If you are going to resort to heat, practice on the other joints and see if you can't burn a slot in the pipe w/o taking the inner outlet of the cat our. I can usually blast a slot by angling an oxy-actetylene flame to hit the pipe at an angle and blast the outer pipe to open a seam that I can jam a wedge of chisel into to peel it off although my favorite tool there is an air hammer with a good chisel made for such jobs - flat or slightly rounded spade with a finger pointing up. The blade starts between the two pipes and the finger opens a slot in the outer piece. I've also seen people use a grinder to cut through just the outer pipe so that they can peel it off.

Of course, I may be remembering the setup wrong and the cat tail will be the outer piece. The heat suggestion is a good one but it takes real care not to burn the whole vehicle down. I sure miss the old asbestos shingles in spots like that! None of the heat suggestions apply unless you can get plenty of ground clearance to work in, either. You'll regret ever trying it!

That cheapo $20 air hammer was one of the best toys I ever bought for jobs like this.

Sometimes it's easier/faster/cheaper to pay a good local shop. I had mine done (muffler included) for about 90$ and they had all the clamps/jacks/etc to keep the tailpipe in the correct position. There isn't much left of my original Gibson cat-back except for the tip end. Next time it is going to have to be a full collector-back replacement. But I didn't have to weld over my head.. I hate doing that because I suck at welding. :)

I've found that going after anthing connected to the cat with a hammer can damage the cat. :( That's why I use an angle grinder or a dremmel with diamond blade for close work. Just split the pipe add a bit of heat from a MAPP torch, then the parts usually twist right off.

Remember to support the pipe. These days you only have a couple of hangers and things start to twist real easy. There isn't a lot of space and if you get too close you will get some serious vibration when the pipe heats up and expands.

Another nice tool is spare muffler clamps. Those are good enough to hold the pipes in place and can be removed when your done.

I was very happy for years with a Gibson cat back.

Replaced it last year with a Flowmaster and high flow cat--which is just a tad on the loud side.

Me too. Till it developed a smiley face on the front end.

ME TOO!

They don't call them FlowMonster for nothin. ;)

I should have just stuck a cherrybomb in there. It did quiet down after a few thousand miles.

Just for hohos went down to Monro and got an estimate. He told me they use Walker and that the installed price for a catback was going to be

435 bucks. A Walker catback is 110 on Amazon and no way would I pay 435 installed for that quality. If he'd said 200 or so I'd have likely taken him up on it just to save the dirty job, but for that price I can get a stainless Gibson catback and do it myself.

With several votes for Gibson I went ahead and ordered it. While the ZJ was on the lift at Monro I noticed that the cat was pretty ratty looking with most of the shield gone so I ordered one of those too (Magnaflow--googling it people seem to think well of them, and it was on sale for less than a Catco), and one of the shocks was leaking so ordered a set of shocks and a steering damper (don't know that there's anything wrong with it but while I'm doing shocks may as well do _all_ of 'em) while I was spending money. And I spotted the source of a rattle I'd been looking for for years--turns out that the exhaust clamps were loose enough to bounce around--for some reason I'd never thought to try to jiggle them.

Since I wouldn't be back and he was nice about everything and I found out so much useful through the use of his lift, I tipped the guy at Monro ten bucks. He seemed both surprised and pleased.

Note for future reference--once in a while tip a mechanic to put it on a lift so I can get a _good_ look underneath.

Thanks all.

If Monro is a chain store then that explains a lot. They are usually just as bad as a dealership. Go find a local owner-operated muffler shop and ask them.

Looked for one--not many around here.

I have ao agree with Doug, sometimes it's just easier to take it to a shop. To replace the muffler, weld it back up, save your back and knuckles should be under $100

Waren't all that hard to do turns out. Helps to have air tools but I could have done it with a Dremel and a pry bar if I hadn't had them. The only really annoying part was when the Gibson clamp broke.