CE light

[JoshE]

Well, i hate for a problem to be my first post here, but unfortunately it is. About two weeks after i bought this car, my CE light has come on. Did the free Autozone check and it's the P0420 code. "low catalyst threshhold, bank one" Now i've searched the forums, but i haven't seen an actual answer yet. The responses i've seen are either the 02 sensor or the cat conv. But no one has seemed to fix this problem, or at least post the repair. My hope is it's the 02 sensor because it's a heck of a lot cheaper than a cat. Anyway, any help here would be appreciated. I really do enjoy this car and would like to clear up what seems to be it's only problem. Thanks
Josh
2000 Protege, 1.6L, 100K miles.