New headlight install and engine light.

[Donstar]

I stopped by a local quick lube place yesterday afternoon and had new headlight bulbs installed on my '15 Sierra.  The technician was obviously familiar with these trucks and explained that he will need to remove the airbox to install the passenger side bulb.  He had both bulbs replaced and me on my way in about 15 minutes.  Driving home, I noticed the check engine light was on.  I didn't have time to circle back but plan to return today.  My assumption is this will be a simple error and easily remedied. The tech was very good to me and waved me out saying no charge.   I don't want to create problems for the employee.  This morning I was thinking that maybe the engine light staying on may not be related to my service yesterday.  I am pretty alert to such things and I'm certain the engine light wasn't on prior to this light bulb replacement.  Is it reasonable for me to suspect that the re and re of the airbox triggered my engine light?

[rav3]

He may have disconnected the Air Mass sensor, which is close to tge air box. Or he may have disconnected some of tge PVC air connections & forgot to get them back correctly. Check to see what the code is.

[Donstar]

On my way to get this checked out, my engine light went out and hasn't reappeared except at startup!  I don't know if it simply needed time to reset itself or if a problem still exists.

[Donstar]

Another idea.  While I was waiting on the technician to change my headlight bulbs, I remember resetting my oil change screen back to 100%.  I did this even though I wasn't getting an oil change.   I go for longer intervals with full synthetic oil changes.  Would this trigger a temporary engine light warning?

[richard wysong]

no, that would not trigger the CEL. It is possible he turned the key on to check the lights with a sensor unplugged and it took a couple of ignition cycles to clear. The code should be stored as a history code even though the lights out.