[DeTomaso] [NPC] Catalytic Converters

[Paul Timko]

My step-son has an 91 olds.  The guy at the muffler shop is telling me that 
the catalytic converter is "breaking up"  I'm not exactly sure what that 
means, but of course he is recommending that it get replaced.  It is 
currently not running well.  The RPMs are unsteady like it is seeking the 
proper mixture but it doesn't have a clue. While this is happening the 
instant MPG is low 4-9 MPG for a Quad Cam 4.  After a little while, it runs 
fine and the MPG is back in a normal range ~20.  I figure that the O2 is 
going, but could the catalytic converter be part of the problem?  I always 
thought that all it did was convert "bad" exhaust to "good" exhaust.

Any thoughts?

Paul
#9270