Hello. Im helping a friend with his GTA, it has probably OEM dual cats and it has come time to replace them since one of the old catalytic converters is rattling.
Does he need stock style cats with air tube on them or can he just put universal converters on it? He wants to keep all the smog and air pump stuff as it is all original, but what to do with the air tube, can it be left as it is and just blow air under the car or would it be a better idea to drill a hole on the exhaust and weld the air pipe in to the exhaust so it wouldn't make a hissing sound under the car if its left unhooked? Or would it be a better idea to just get universal catalytic converter that is air tube adaptable? Another question is what would you guys recommend, staying with dual cats or change to a single cat? My friend would like to put universal high flow cats on but they don't usually have the air tube on the cat where to connect the car's air tube.

 

If he wants to keep it all orginal, go with a more factory replacement? Does he live in a smog state where he has to get yearly smog testing done?
89-92 Camaro/Firebird 305/350 V8 Dual Cat Y-Pipe Stainless Steel - Hawks Third Generation (hawksmotorsports.com)

 

He lives outside the states. Smog testing is not an issue. I have been looking for universal cats, 200 cell.
Would the air tube be a good idea to weld on the exhaust so it can function just as usual even tho universal cats doesn't quite likely need the extra oxygen if they don't have the air tube pipe on the side of the cat. If the smog pump air tube is left unhooked, would it just make a hissing sound under the car?