OK, this might be lengthy but I'm kind of confused. A few weeks ago my CEL came on, then a few days later went off on its own. Then, it came back on again and stayed on for several days. I took the car to my mechanic to have him pull the code and it shot off code PO430 (Bank 2 cat efficiency below limit). He replaced the fuel filter (it was very clogged, couldn't even blow thru it) and then cleared the light. All's well then 300 miles later (after a road trip to the desert and back) the CEL comes on again. It was on for about a day then went off on its own and has been off for several days now.

From what I understand, once the CEL comes on, it has to be reset to be turned off, but mine seems to have a mind of its own. Any input would be appreciated. The light is off now so I'm not too worried about it, but I think it's only a matter of time before it starts its antics again.

Thanks for your help.

~C