You might try a belt sander to even things up on the mating faces. �That suggestion came too late for me to try it when I had the same problem. �I'd already tried what the nearby Advance Auto guy recommended; PermaTex spray on Copper Seal (you may want to verify the name) worked for me. �I actually had shaved down the second gaskets so they more closely filled the gaps, then sprayed heavily the copper stuff.

Stephen

________________________________
 From: Edward Maglott <emaglott3@GMAIL.COM>
To: vanagon@GERRY.VANAGON.COM 
Sent: Saturday, July 20, 2013 5:24 PM
Subject: exhaust leak, header tubes to collector on 2.1 engine
 

Yes, I'm putting it back together now.� Where the 2 header pipes join
to the collector, there is not a lot of metal there around the
circular surfaces that must make the seal.� I cleaned the surfaces
with wire wheel and used nice new gaskets.� I've heard of using
double gaskets there and wondering if that's the best way to proceed
or if there are other suggestions.� I wish there was some sort of
sealer that could withstand that environment but I don't know of
one.� Thanks for any tips.

Edward