ok ima brake it down real quick...i bought an 88 fc se and its its all stock besides the intake and exhaust...heres my problem the whole exhaust system is custom GHETTO AS F***. from the manifold all the way back the exhaust manifold is custom as well but the O2 sensor is only reading one exhaust soo i know i have alot of carbon build up my homeboy give me a racing beat header to put on im gunna do that this weekend...i bought an hayness repair manual i was lookin though it and my FC is N/A and the diagram says on the N/A theres the manifold then the 1st pre-catalytic converter, 2nd pre-catalytic converter, and the main converter then the mufflers...so theres 3 cats on my car? the custom one thats on there now doesnt have a cat soo im lookin for a universal cat for my car i need to pass a smog check but am i gunna have to buy 3 cats??? hahah....CAN SOMEONE HELP ME OUT HERE?

 

You can make the car pass a sniffer test with one cat provided the remaider of the emissions are in place (air pump, etc).

Use the RB header and a mid pipe with a universal cat and you're done.

You may fail a visual so find a lazy inspector.

 

I dunno - Cali is pretty strict about that sniffer crap. You should probably have a cat as close to the header as possible for hot exhaust to super burn any extra hydros leaving the engine. I made a flanged cat and flanged the exhaust and made a pipe to fit also. The cat comes out in 15 minutes on a lift and I have a pretty straight exhaust.
Sounds like you don't have much in the way of equipment. Good luck.

 

that was my plan to find a universal cat and have it welded to the mid pipe that was on the ghetto exhaust thats on there...but i mean i just want to pass smog then i planed on taking the dual exhaust and cat out and i was gunna buy a mid pipe and run one exhaust instead of dual...