91 YJ catalytic converter?

Get it welded in. (in some states the cat must be welded on the engine side, has to do with emissions laws)

A good local muffler shop should be able to do the job for $100 or so.

In what states does it have to be welded? Or is this more California craziness?

I can understand the OP's concerns about economy, but a budget converter installed on the cheap isn't going to last long. Mine (OEM part) has been on there since the emissions recall of 1995, and is still going strong. I doubt that the "guts" are still in it, but that is what a free flow exhaust is for, to let the converter chunks out. Seriously, this isn't something you want to go cheap on.

Cheers,

Earle

I got my cat from

Could be. I checked the Oklahoma regs and they don't specify. Thought the local muffler shop told me that when I was thinking of swapping to a bolt-in unit.

The only problem I have with clamps is on many installs the pipe tends to rotate. A spot weld is usually all it takes to keep things in place.

It's not a safety item and it's not going to seriously effect performance or fuel economy, as long as you can pass inspection I don't see anything wrong with cheaping out on a converter.

That being said if you plan on keeping the vehicle for a long time then spend the extra bucks for a good converter, it's worth it to not have to mess with the exhaust system.

Jeff DeWitt

Four letters Jeff, "r", "u", "s" and "t". It's amazing how fast cheap metal tries to get back to the earth it came from. That said you don't have to get ripped off by the stealership. Just get a quality brand name component, and you won't be sorry.

Yep, exhaust system work sucks. I have known people to attack stubborn exhaust bolts with a 44 Magnum.

Saludos,

Earle

That's why the make air hammers and sell muffler specific chisels for them . With that and a good angle grinder, I fear nothing!

Just for fun, have you ever tried to weld on one of those "aluminized" jobs? Between that and some grades of stainless, clamps are hard to avoid.

Muffler shoppes will tell you anything, especially if they get to weld the new unit in.

If it is stubborn enough to need a spot weld, usually there is another problem, such as mismatched pipe, a joint not inserted all the way or a clamp the wrong size. The stainless steel exhaust components are pretty slippery, but if you run the engine, retighten the clamps and repeat usually even they will lock down eventually. I have one that I am giving up on and will spot weld later today.

Cheers,

Earle

True, but to weld on the bolt adapter would have been more money for the shop.

My problems always pop up when the exhaust hangers put torque on the pipe. In the ZJ they are all off to one side so the whole assembly tries to rotate.

Its been on since March I crawl under and check things out once in a while and have not noticed anything yet. I used band type clamps. Not sure if that would make a difference. I'll keep an eye on mine.

I've had that problem. I used a muffler clamp to install the muffler and cat and have been retighting the clamps but the buggers have still rotated about 45 degrees on me. Gonna loosen the clamps and spot weld the buggers in place and then retighten the clamps.

Local specialty shops tend to know the regs pretty well and it is usually not in their interest to overly lie if they have competitors. There are some really good aftermarket cats available, although as someone noted, some states ban universal fit styles more for political than technical reasons.

Yeah, even the expensive Banks sleeve style clamps can be problems. Somehow I kept managing to loosen and misalign the connect to my cat back just enough to leak a bit until the service manager had a tech just put a couple tack welds on it. The stainless was not a problem, and it hasnt loosened in years...sadly that dealer is defunct and havent found another good one in two different states yet.

Yeah, then those assembly notches have the murphys law of always aligning to create a tiny leak.

Then that rear cheap rubber exhaust hanger gets 3 minutes old and tries to droop your cat back until you get ticked off and create your own with a bit of neoprene clamped inside the standard cheapass mopar rubber hanger.

Tell me about it. I had to replace the rubber hanger in the ZJ. They don't make the original part but they have a "newer better one". That means it doesn't fit. Well, it does if you take a sharp knife to the darn thing and use a drill to open up the holes a bit more.

The 95 has a glorified oversized rubber band that the hanger pin fits in. That all fit perfectly but kept allowing the aftermarket catback whack the rear axle on heavy bumps. There is a cavity at the bottom of the rubber hanger where a cut neoprene suspension bushing fits like a charm, and stays surprisingly well in place with just contact cement.

Got the same metal surround, think I'm going to do that next time.