I plan to replace my manifold gasket on my '93 Accord SE. I've heard that you should apply some Permatex Copper gasket sealant on each side of the new manifold gasket. True? Thoughts are welcome.
And...should I also apply some to the flanges at each end of the front pipe (which I am replacing) for good measure? I noticed that there was no gasket connecting the CAT to the downstream end of the previous front pipe. Is that normal?
Thank you all!

 

Doesn't the 93 SE have the 4-2-1 exhaust system, it should have a dual down pipe?

If you are trying to replace gaskets on the stock exhaust doesn't it use 2 O-Rings, not a flat gasket?

Even if it is an aftermarket exhaust or a flat flange exhaust you should not need to use sealant. So long as you tighten it using even pressure to all the 3 studs evenly Don't tighten one nut 100% and then go to the next.You want to tighten them in stages. This will avoid crushing/bending the gasket and it will seal without issues. Hand tighten all three then snug each one with a wrench, then go ahead and apply some pressure to them.

Note: Make sure that the flange surfaces are flat and free of scratches or dents. Some of the cheaper headers can have imperfections.

If you have a race only header that uses slip on flanges, that is a completely different story.

 

the 93 SE should have the 4-2-1 system unless it was replaced by a previous owner.

The RTV won't hurt anything and it may help if your surfaces are imperfect, however, you shouldn't need it. There should be a gasket between the downpipe and the cat, definitely would recommend getting the gasket instead of applying RTV, its only a few dollars.

 

Yes, this has a 4-2-1. I have a new exhaust manifold gasket (for between head and manifold) and wondered about this copper RTV sealant. Maybe a thin film won't hurt at all connection surfaces? That's what I was wondering about.

 

There are people that use sealant and the people that cuss the people that use it. The people that cuss out number the people that use maybe 100 to 1. Why if the factory didn't use it why would you?

 

rtv will not hold up as an exhaust manifold gasket and it not needed at all, even with any other gasket. Just use the metal crush oem gasket and make sure to torque from the inside out and you will be fine. The rtv will burn off in a matter of minutes anyhow.

You do NOT want an exhaust leak.

 

I hear you. Sound advice, guys. Thank you. I'm gonna take your advice and go with gaskets alone. Thanks again!