If you've recently filled up at one of the Phillips 66 gas stations located on a pueblo (such as the Santo Domingo and San Felipe stations along I-25), you may have gotten some bad gasoline. My husband filled up at Santo Domingo a few days ago, and the check engine light came on afterward. I called our mechanic, and he's been hearing similar problems from others who had just filled up at these pueblo stations. So far, not much damage has been reported, just rough-running cars and glaring check engine lights.
--If your car is running, just drive through your current tank of bad gas until it's almost empty.
--Fill up at a Chevron or a non-pueblo Phillips 66.
--Drive 3/4 through that fresh tank.
--Take it in to your mechanic, and they'll reset the check engine light.
--If the light doesn't come back on, and your car is running fine, problem solved. If the light comes back, or if your car is still running rough, you'll need to run diagnostics.
I'm sorry if this reduces business at any of the stations, but it's not worth damaging your car. Stop at the pueblo stations for chips and soda, but don't get your gas there.