The only CATS that will give you a code are the pre-cats located in the exhaust manifolds.. which is why it costs so much.

I would either guy your pre-cats and get MIL eliminators or just get some MSDS headers... for like 1/4 of the cost of getting the crappy stock ones replaced.

04 Subaru WRX "Eurosport bling bling fast and furious tokyo drift" "They have diarrhea of the mouth, and constipation of thought"