smoke from exhaust gaskets

[bumperbozo]

i replaced my exhaust manifold gasket, which also required replacing the cat and flange gaskets. for the first hour or so when i first fired up the engine, there was smoke coming from all three gaskets and i though "i'm such a loser. they are all leaking"

today i looked and they don't seem to be doing that anymore. was that just the gaskets curing or something? my fingers couldn't tell if anything was coming out of the seems. how do you definitively determine if there are any small leaks? do i need IR goggles or something?

also, looks like i need to replace the pipe between cat 1 and and what appears to be cat 2 (allthough i have a federal spec car so i don't know why there appears to be a california cat on there.) it's $220 for the OEM toyota part. would it be much cheaper getting them to rig something up at midas or something?

[IVIarc-Antoine]

i'm not shure but i heard that new exhaust gasket will burn a little bit and that may cause light smoke at the end of the exhaust

if you want to make a test just rev the engine a little bit and listen near the flanges if you hear something like a "pfffrt" it might be a leak

hope it will help !

[MR2Jedi]

If you had a leak, then incorrect signals were sent to O2 sensor(s) and you may have accumulated some carcon/soot in your exhaust sytem.
With the new gaskets, and proper flow, it probably just burned off the crud, causing smoke for awhile. If it's stopped smoking,I wouldn't worry about it.
As far as cats, some of the autoparts
stores sell universal cats that work just fine and are 1/2 the price of the dealership.