So i had a CEL come on the other day, and i got it diagnosed at autozone

KS fault and catalyst system left and right bank fault
i assume the KS is due to the cat system because its happened before with other CEL problems and went away after fixiing those, also my gas mileage isnt any lower than normal

the car sounds and runs perfectly normal, no smoke or anything
and the CEL actually went away for a few days, although it did come back

just wondering what you guys think the problem is, and how expensive it might be

thanks

 

What were the exact codes...

0304 - knock sensor... what about the others?

 

0420 and 0430 i think
i cant remember

 

If the light is still on you can retrieve the codes yourself - look in the ECU sticky for instructions. If the light is off, then don't worry about it until it comes back on.