One week ago it came on, dealer found nothing. Came back on tonight. What could be causing this? :-(

M.

 

Now 1 day later ... the Chk engine just disappeared. Go figure!

M.

 

And today it came right back. No obvious reason. Going easy on the cruise control when it came on. Weird

Micho

 

A ground fault could cause a check engine alarm.
Sometimes cables looses partialy its insulation. for example if a cable touches a hot surface it looses the insulation rubber in that point and if this cable is free to move maybe a contact with the engine block, chasis or any metalic part etc causes a temporarily ground fault (maybe in one sensor).
I suggest a detailed check of all your cables, inspect visually your sensors and connectors, watch for a cable with bad position and so...
And see what happen...

Anyway you have to check all your sensors with the apropriate computer interface.

Regards
UHZT