90q exaust/cat options

[Andrei Kogan <abk@phy.duke.edu>]

I had the exaust system checked  today (1988 90q) and was told that the
Catalytic converter interior got cracked and the bits of it made it into
the middle muffler, which accounts for the horrendous rattling/gorgling
noise we here occasionaly from under the right rear seat. Could someone
recommend the replacement options? TPC
quoted me $300 for the cat and $170 for the middle muffler (italian made).
I am wondering if I should go with that or use this opportunity and
consider upgrading the  exaust system. I cannot really afford even
repairing what I have at this time, however, since this is  going to be an
expensive repair maybe  I should wait a few months till when I can spend
more. Something should certainly be done before May when the car is due for
inspection.

All Suggestions and opinions are welcome.

Andrei