Leave it in, as long as it is working properly, else, you will fail the SMOG / Emissions test if the light does not come on at the start/off after ignition. I have a different problem, my CEL comes on at pre-ignition, turns off after ignition, and comes back on after 45seconds or so. If the RPMs are 1100+, the light stays off. If the RPMs are at normal idle, the light comes on after 45seconds. If I rev the engine every so often (within the 45 sec window) the light stays off. Doe anybody have any ideas?