I have another question for those with experience.  Before I attack the
broken motor mount screw, I check the exhaust system for leaks.  1-3 pipe
flange gaskets are leaking at the head.  In addition, where the O2 sensor
screws into the Y-pipe is leaking between the sensor and pipe.  All other
gaskets are good.  The question is how long (or how many miles) do the
flange gaskets usually last?  Is there a set time when these should be
serviced just like other parts of the engine?

What is the best way to handle the O2 sensor leak?  I am guessing that there
is a bad spot in the thread that is letting the leak occur.  Could be a
crack but the air is definately coming out between the hex wrench part of
the O2 sensor and the top of the threaded flange on the Y-pipe.

Just trying to determine if it is normal to replace all of the gaskets or
just those that are leaking.

These leaks would seem to explain the slight drop in mileage and rise in HC
reading when the smog was done.

William