'90 V8 Cat Converter

[BernieD1@aol.com]

My '90v8 (60k mi.) has developed a loud metallic rattle coming from the 
undercarriage. It's most noticable at low speeds during light acceleration. 
I've been told by 2 separate shops that my right side cat converter has gone 
bad. Seems premature to me. According to the owner's manual if the cat is not 
operating properly, a warning light on the dash should come on. However the 
CAT light on the dash has NOT lit up.
Any BTDT's? Anyone have any ideas where to get one - other than Audi?
TIA
Bernie Dubin
'90v8
'93 miata