Rob98LS1

iTrader: (5)

Hey, not sure where this goes but just a quick question.

After installing full exhaust on it and removing all of the emissions equipment, I had 12 new codes being thrown. It has been this way for the past year of so. Anyways, my check engine light has never gone off before since then and I thought i read somewhere that the codes must be cleared for the CEL to go off. Right? Point is the other night i was driving home and the check engine light suddenly turned off until i got home. then it came back on.

How is this possible? I thought the codes must be cleared before they are able to be turned off. Maybe I am missing something. This isn't a big deal but just didn't understand. The car pulled very hard by the way haha.

ULTIMATEORANGESS

iTrader: (4)

just get it tuned. i had that happen after my LTs were installed.

Rob98LS1

iTrader: (5)

that wasn't really my question though thanks for the response!

greysteel_M6

iTrader: (5)

I don't know, but your plugs should fouling out every so often untuned.

Rob98LS1

iTrader: (5)

after 20k miles on new spark plugs, i checked them, they looked great. I installed new ones anyways though. Ya, anyone else know why this happened?

ErikElvis

iTrader: (1)

Who knows. If the SES codes/checks werent completely deleted they wont go away. Everytime you drive the car it will check for those components and if theyre not working the SES will set off. And regarding your question if you have it tuned they can turn off certain checks and ses lights. You do not have to get the codes cleared first. The emissions equipment you removed will continue to set off lights until the PCM is told not to check them anymore.

Rob98LS1

iTrader: (5)

oh you don't have to have them cleared first? I thought that's how it worked on these cars. That was the ONLY time in over a year the cel turned off, just weird.

waldershrek

iTrader: (1)

Well said