Check Engine Light, Engine Misfire, Flashing Lights, and Low MPG
I have a 2014 Malibu with just under 6,000 miles (mostly highway) [VIN: 1G11C5SL4EF107999]. I have a series of issues with it - maybe they're all related, maybe not.
Background: A month or two ago the check engine light came on while driving in city traffic. Simultaneously, the auto-stop re-started the engine at a traffic light the car began shuddering violently and wouldn't go above 30 MPG. The dealer reset something in the computer to make it stop. I assumed everything was fine now.
I had my first oil change yesterday at the same dealership.
This morning the check engine light came on in a flashing pattern. I was going about 55 MPH on a flat country road. I drove for about 2 miles and the light then went off. When the light went off, the entertainment system beeped one time (the same tone for the voice control activation alert) and the interior entertainment panel lights grew brighter for a second. When I searched for reasons for a flashing check engine light I read it could be an engine misfire detected?
In addition, I have much lower gas mileage than promised. I'm averaging 26 MPG - instead of the marketed 36. I'm wondering if there could be a larger issue involving the computer or fuel injection system that could explain both the chronic check engine/misfire issue and the low MPG. One dealer told me the MPG issue was due to the temperatures outside and/or from using the remote start. It has warmed up, I've stopped using the remote start and it has not fixed the issue.
Additionally, the interior lights (entertainment panel, etc.) frequently and randomly grow brighter or dim, with no perceivable pattern. I doubt this is due to changes in cloud cover (could the light sensor really be that sensitive?) I'm concerned there's an issue with the sensor or electronics.
Finally - and yes, this is a minor thing compared to the above - the Siri Eyes Free isn't functioning correctly. The phone display still lights up when I interact with the Siri interface, although the other functions seem to work okay.
I've tried getting answers on all these issues from two dealers with no success, and I'm getting very frustrated. The main reasons I gave up my Ford Fusion and switched to Chevy were for the Siri Eyes Free and the MPG, which appear to be moot points right now.