Lemme get an opinion on this:
I've been reading through that "P0420 what do i do?" thread and gotten some good info. Heres what happened- back in 05 i had the MAF done under warranty (used car) the CEL came on right after so i went back and they replaced an o2 sensor and did an ECU update. Now, the light came back on a month ago and it was P0420. then it went off. then it came back a few weeks ago, 420 again. went off a few days later. it came on earlier tonight, went to advance auto and they pulled two P0430 codes which is bank 2!

so...when the 420 came on, i called the dealer and he pulled my service record, said he can try to check if my car falls under the category for the TSB and can do an update, but if not i'd need a new "front tube and o2 sensor" now with this P0430, which o2 is going bad? there is no oxygen sensor after the main cat, so it means either my front precat or rear is going bad, or one of the o2's. i can either get a y-pipe and see what that does, or take it to the dealer and pay 100-150 for the diagnosis and *possibly* a reprogram. So those who have more experience whats going on?

 

the light is still on today after 3 restarts, so idk