just thought i would let you know i have had a P0420 (Catalyst Low Efficiency) for a long time and never got around to changing anything but two days ago the CEL went away!!!!not sure why but i'm pretty happy so i thought i would make a lil post about it lol.i checked my codes and it had some though P0420 and P0513 (i used the wrong key) i'm resetting the codes so lets hope that the damn CEL doesn't come back!

03RT did you ever fix your problem with that P0420 code?

 

Nope I never had any time to try and fix my P0420, so its still lit up...i'll get around to it eventually though.

 

any reason as to why it would just disappear?

 

bulb burn out?

 

nope it still turns on when the bulbs test (key in the on position)

 

lol ok.. dont know how many people i have known that were like dude my cel went out today guess it fixed itself. to find out the damn bulb burned out.. actually my boss did it..lol

 

lol thats what i thought at first but when it lit up during the bulb check, it was a lil more puzzling