Is even a slight exhaust leak unnacceptable?
 

I thought about this after reading through the most recent x-pipe thread here. I installed an x-pipe and hi flow cats from Roger a month or so ago-they're great products. I used the supplied band clamps as well as one of the silica fabric exhaust wraps instead of fiberglass to seal the joint. Fiberglass fabric just makes a mess when it unravels and the silica stuff is rated to 2000 degrees. Anyway, I use an old disco smoke machine to check for leaks (I place it on a cinder block and blast the outlet into the tail pipe). On one of the four clamps, I still get a few wisps of smoke coming out at the point where the ends fasten together. It looks like a minimal leak, but I assume that some leakage will always occur at a few of the joints on any exhaust system. Is this the case or should I get back under the car to make it 100% leak free? I don't spend a lot of time in the car with the windows up and the engine idling, so I'm not too worried about unintentionally drifting off into the next world from CO inhalation.

Cool trick. But the smoke's gotta go somewhere when ramming it up the tail pipe. Exhaust blowing out the tail pipe probably won't notice enough resistance to need to vent though the tiny gaps.

Of course, you need a good fit prior to the cat (unless you removed your cat?).

It is always better not to have any leaks.
If it is leaking past a cloth and band clamp I would tighten it by adding more cloth.
A leak at the cloth will slowly get bigger like a hole in a dyke

Not that there's anything wrong with that.:eek: