how would u check the cat on a 81 f-150 with a 302 2 barrel holley i know there is a way involving a vaccum gauge but besides that im clueless

 

What seem's to be the problem with it?

 

truck wont pass emissions exhaust seems quiet and carbon comes out exhaust i know its not oil comin out because the engine only has like 15,000 miles on it

 

The catilyitic converter would not do this. How long has it been scince your last tune up?

 

Usually when a converter is bad the car will fail on Nox, excuse my spelling. But thats not always true. I think you can check it by temp. I may be wrong but I thought if its over 500deg it's probably bad. Most muffler shops will check it for free, at least where I live.

 

The best time to take an older vehicle for an emissions test is when it's nice and hot!

 

You would be right on that.

I forgot one thing you loss power when the get clogged up to.

 

ok cool i just got to find one of those temp guns and shoot the exhaust pipe before and after the cat and if its alot hotter before than after that means its clogged

 

It is supost to run a little hotter than the exaust.It is ment to burn exaust gas's. But not to hot.