The vacuum acting as a blower really shows things up on the exhaust
system.  Got most of the cracks fixed in the #1-#3 pipe.  New gaskets
and enlarged a couple holes just slightly so everything just slips on.
Can whip that sucker in really fast now.  Got it all torqued and checked
under the vacuum blower again.  Still a couple of small cracks which I
will have to fix yet.  Decided to check all of the gaskets.  All are
properly tightened.  Seems that all but the Y-pipe to the Cat are
leaking.  Three of these are new gaskets properly torqued.  Seems that
the bolt part of the flanges seems to be fine but the part in the middle
of the flanges is leaking air.  I am using the metal one side gaskets
which is correct for this van.  I am looking for ideas for what to do
next to solve this since I don't think the van will pass smog even if I
get the pipe leak fixed.  The O2 sensor is adding more fuel.  Do the
flanges warp?  Can they be fixed or ground flat?  Is there a sealent
that can be used on the gaskets that won't affect the O2 sensor?

William