Muffler patch kits - do they work

I have a 1998 Honda Si with 253,000 Km (~165,000m). Mechanic tells me I have a pinhole in the muffler and exhaust manifold. Starting to sound a little rough. Don’t really want to put $ into her.
Do these kits work? If it holds a year I’m laughing.

You are putting a patch on rust, it will only last until the rust catches up with the size of the patch. You might get 6 months. Might get 3, might get a week. Hard to tell. Drive with your windows open so you don’t get carbon monoxide (spellcheck!) poisoning in the meantime. I hope that gives you a hint of the possible effects of you being too cheap to fix the car correctly.

I agree with @Mustangman. A better solution “if” the hole is a pinhole and the muffler is rust free otherwise is to use a sheetmetal screw and epoxy. I use this only as a temporary fix however.

Agreed. Muffler patches are not reliable. As for the exhaust manifold, if it has a hole (more likely a crack) replacement is the most reliable option. There should be lots of them available used. I once had a Toyota ex man’s crack welded, and it held up for the remaining couple years the vehicle lasted, but I think I was just lucky.

Carbon monoxide is the big danger in exhaust gasses. Carbon dioxide is the bubbles in the Coke in your go cup.

It is certainly worth a try. You may indeed get a year’s worth of repair from one cheap kit. If it doesn’t last long enough for you, you can reconsider the situation.

I’d use a patch like that on the muffler, but not the exhaust manifold. You might try having the exhaust manifold welded by an experienced and knowledgeable welder, but don’t be surprised if it doesn’t hold.

Broken exhaust, brakes and tires can kill you.

At the very least drive around with a cracked window…

@Gord777 - If the exhaust is rusted/cracked, I wonder how the suspension/ball joints/etc. are doing - have those checked over.

I’ve never had any luck with them. They just burn through, even with wire and sheet metal. Might be able to weld the steel tube but not the manifold if its cast. A guy actually welded up the end of my cat that had rusted loose and it held for a couple years. The parts to do it right though might be cheaper than you think and exhaust leaks can be deadly.