Kirby's a 2011 MCS with about 2K miles. About a week ago I got my first yellow engine light. I couldn't get a service appt until tomorrow, so in the meantime I fiddled with the gas cap and then drove it a few times for errands, and finally yesterday the light went out. I still have the service appt. scheduled for tomorrow - my question is, should I take it in for the appt and at least get the error code read (does something like that end up on a Carfax?) to confirm it was the gas cap, or just be glad the light's off and move on? There weren't any performance issues while the light was on.

-Steph

A lot of times the engine lite can simply be just a gas cap not providing a complete vacuum. But if it's been more than a day after you fiddled with it (more like next starting of the vehicle +/- a mile), yes, caution on the safe side and take it in. Can't comment on the carfax: don't know.

I got a check engine light several weeks ago. The light went away after a day. When I took my car to the dealer to see why the check engine light came on and went away, they found my car had a faulty coolant temperature sensor. My car had slightly over 2,500 miles at a time.

I don't think you need to go in for Service, Gas Caps are known for being problematic. Just keep an eye on things, if your ever wondering what the Yellow Check Engine Light means there are numerous OBD Readers on the market, it might be a good idea to look into one of them.

Thanks for the input, all. UAL_Kingpin your experience definitely caught my attention since you have a 2011 with similar miles. Fortunately the dealer's not far from my house so I'll go by in the morning and see if they can do a quick error read (yeah right) and go from there.

I like the ODB reader advice too. That'd be a much easier route to peace of mind.

-Steph

I have an OBDII reader which was useful to me when fixing one of my other cars. Hooked it up to my MINI just to see. Shows lots of information even when driving, not just error codes.
Many autoparts stores will read your codes for free though some will ask if you have constant CEL. Just go when they are not busy.
No way any codes get to Carfax. You pretty much have to have a big ticket insurance claim for that.

Although if service work is done on the car the Carfax will show that. I ran a CarFAx on my MCS and it shows all the service work completed on the car. Oil changes, brake fluid changes etc.
So I would assume that if service work was done on the car it would be reported on the car fax. The car fax is pretty all inclusive. It even noted that my Mini has the extended service contract.

Update: went to the dealer and they were cool enough to run error codes while I waited (it helps to get there at the crack of...). Turns out it was a coolant temp sensor fault. I think we both got a bad batch on the assembly line, UAL.

The interesting thing was, when I described the light on/off and asked if they could run the codes they didn't really perk up until I said it's a 2011. A guy in an office behind the service advisor actually chimed in and volunteered to run the codes right then. Now I wonder if they've seen this quite a bit and he had a pretty good idea what they were going to find.

Good thing - I was beginning to worry that after 20+ years of driving I still didn't know how to work a gas cap.

Update 2: the problem was a faulty thermostat. They kept the car overnight to complete the fix but I got the car back today, put 120 miles on it and didn't have any problems.