I have a 2011 Honda Pilot with 245,000 miles.  It occasionally has the check-engine light come on, along with the VTM-4 light.  It has happened before, eventually going out for a few months before reappearing, but this time there is also some rough idling when the car is first started, even started when hot, such as restarting at a gas station.  After I start moving, the roughness stops and the engine runs fine, but the lights remain on.  I've had a couple of shops scan it, each with a different diagnosis. I haven't pursued repairs yet because neither mechanic impressed me very much, stopping their efforts once the first abnormal code was seen. Any thoughts?  Thanks!  By the way, I'm located in southern Maine.