E420 evaporative emissions system fault
 

Several moths ago the low fuel light on my E420 started flashing while there was still a lot of gas in the tank. It would go out when I turned off the ignition and would not come back on upon start-up. Then, usually when transitioning from street to driveway or vice versa, it would sometimes return. When I took it into the dealership for service I was told that my gas cap was the culprit and the computer was reading a leak in the evap sysyem because of it. The cap was replaced. Well, the problem has returned less than 7,000 miles later and has now triggered a "check engine" light which will not go away. The dealer reset it and said it is a leak in the evap system and could take hours to locate and fix. After paying 4.5 hours to have the spark plugs changed I am not in love with this idea. Does anyone have a suggestion as to the most likely source of this leak? The dealer said that it is probably triggered when the chassis is stressed/twisted while entering and /or leaving a driveway which causes a cracked hose or fitting to open up and create a leak. :confused: