Do CEL code clear by themself?

[troop1]

all CEL codes will clear themselves if the perimeters for setting them are either self corrected (which doesn't happen often) or enough key cycles have passed without a fault. check your fault code history to see which codes set and cleared themselves.

[steved0x]

Originally Posted by troop1

all CEL codes will clear themselves if the perimeters for setting them are either self corrected (which doesn't happen often) or enough key cycles have passed without a fault. check your fault code history to see which codes set and cleared themselves.

The Bentley manual describes how they clear themselves if the error conditions don't repeat for the next X drive cycles. I have got a couple that show up from time to time, and then they clear themselves. Since I have been to FL they haven't shown up, until the other day I haven't even read them yet;; I think it is one of the secondary O2 sensors. I have all the troubleshooting steps, but just haven't fooled with it since the car is running great, and they haven't been on (until the other day, sigh...)

Steve