I'm getting a P0430 and P0463 cel code. Cel used to come on and off when the weather got warm then go off and stay off when it got colder in winter producing this code. Now it just stays on. The car doesn't seem to be misfiring and runs fairly smoothly. If it were the cat it seems the cel light would have come on and stayed on but it took 5 years for that to happen. Other possibilities have to do with the fuel sensor but I have no problem with the level gauge working and again if it were that the cel would have come on and stayed on way back 5 yrs ago when this first started happening. Any ideas are welcome. Please hurry since i need to smog this thing real soon. Thanks in advance to all who respond.