My mechanic tells me he needs to replace the left side catalytic
converter on my 2000 Pontiac Trans Am, (v8 5.7L automatic, 76,000 hwy
miles).  He says it is a California emissions system and needs a
specific CA emissions converter.  I live in New Jersey and have to
pass NEW JERSEY inspection by the end of this month.

I found many left-side cat. conv. for my specific car on websites, all
for under $300.00, but all say "Exc. CA".  Mechanic says it is hard to
find the CA part but it HAS to be THAT one to fit, and could be
anywhere from $200-$1500.

He is calling me Monday (5/23) with a price.  I don't want to get
ripped off.  Is there really a difference in the CA vs non-CA that
would prevent non-CA converter from fitting/working, and should that
difference increase the price by very much?

I would like to know how much I should expect to pay for the CA-part,
and what the specific reason is that a non-CA part would not work for
my car (for example, mechanic suggested that whatever parts it has to
hook up to may be different).

Any verified weblinks or phone numbers that I could look at or give
him as proof of the price range for the CA converter would also be
helpful.  If it makes any difference to the answer, I have to put the
part in this coming week in order to get inspected in time.

I need this answer before 7am Monday, 5/23.