Is it worth it to replace a cat with not yet 60k on it when I have already had the exhaust replaced and will have a header installed soon? I have an 02 SC2.
In short, the answer is no. The stock cat is already a "high flow" cat, and if there's no need to change it out right now, it's just money down the drain. And aftermarket cats generally do no last as long as OEM. Before i gave away my 97 SL2, it had 200K miles and the cat was still working as intended (california smog test). I wouldn't recommend changing it out for any reason except that it's going bad.
I had the exhaust pipe from the cat back replaced with 2.5" mandrel bent tubing and a Magnaflow muffler put on. Soon I will have the factory header replaced with an OBX. I thought it might be a good idea to go ahead and have the factory cat replaced with a Magnaflow one so that everything from the header all the way to the muffler was new.
I have not heard that aftermarket cats wear faster. I have heard that the factory car is a hight flow, but I cannot find any documentation to show the flow rate versus an aftermarket one.
Thanks for the info. Any additional knowledge you can share with me is appreciated.
Catalytic convertor 
Linear Mode
