Alternatives to stock cats?

My cats are bad, throws a P420 code. Last year I added O2 sensor spacers to avoid the problem and get past an emissions test (It was a temporary fix, don't troll me). Now it's time to actually replace them.

Local shop quoted me $3400 to replace them with OEM cats, I need something cheaper, preferably high-flow.

Also.... do I need to replace the secondary cats too, or just the primaries?

 

take a look at flow master universal cats

 

Hoping for a bolt-in replacement. Those need to be welded. In CO only OEM cats are allowed. I don't mind using non-OEM even though they're not allowed, but I don't know that I can find someone willing to weld them in.

 

Bolt some cats on it. That work.

interesting I didn’t know that about CO. I thought CA was the only one that was strict. For example CA requires CARB approved cats that cost significantly more than non CARB cats.

 

magnaflow makes oem quality cats

 

Was just about to say the same thing

 

If you dont use a OEM cat, theirs a good chance it could throw a p0420 code again. A lot of newer vehicles are very sensitive to the cats. Iv installed a number of non oem cats on customers cars at their request and most of them still throw a random p0420 code now and then. If you go the aftermarket route, you may still need to run a o2 spacer