Permatex 80335 Muffler and Tailpipe Sealer, 3 oz., Plastic

Great stuff to use when sealing up an assembled exhaust kit for my f150. Easy to apply. Been on for 6 months with no leaks.

I searched for a long time before deciding on this product to provide an extra seal to my exhausts catalytic converter flange. The flange in front of the cat was leaking, and so I r&r'd the old bolts, and then I wire wheeled the mating surfaces. Despite this, there was still a decent bit of pitting, and this 'sealant' worked well to fill in any imperfections that were present. I did this roughly 6 months ago, and daily drive the vehicle - no leaks from the area that was patched. I even reused the old 'donut' gasket since I didn't want to spend any extra money or time on this repair. I would recommend this to anyone who is working on an older vehicle with a rusty exhaust, or to anyone who wants to exercise an abundance of caution when trying to prevent any exhaust leaks following a repair.

Only good for a temporary fix. It lasted just a few months sealing a small leak when connecting two new pipes with clamp. It was easy to work with. It just expected it to last a little longer when paying more for the high temperature formula.

Works good on seams that leak on a muffler. Used all of it. Not expected to be permanent but, works as a great improvement for muffler leaks. Less expensive than replacing a muffler.

Solid stuff that seals/dries hard and stays in place. Good for a bandaid fix and/or for ensuring tight leak free connection on a band clamp.

This is decent and can work to seal leaks, but only when applied in a very thick layer. Thinner coatings quickly flake off. Dries like cement so it's very brittle. Any movement in the exhaust fitting will cause it to crack.

I’m pleasantly surprised by the usefulness of this stuff. I feel like a real muffler man

Good product. Worked well as advertised.