I having a problem with check engine (electronics) light on 1998 E320 wagon.
The car came from my grandfather w/50k miles and the check engine light ON. Dealer confirmed previous garage diagnosis, check engine was due to bad mass air flow sensor, and replaced MAS. No problem for a month or so. Wife driving and the check engine light came on. Dealer found code indicating emission control issue. They checked the pressure in the gas tank and Identified gas cap as the problem, BUT, their claim was that the gas tank filler neck was out of round so the gas cap was not sealing properly. Their solution= $1500 for a new gas tank. We chose to forgo that option. Left the dealer with the reset check engine light, filled the tank and drove w/out incident UNTIL the low fuel light came (does it always flash?) as the low fuel light came on, so did the check engine light. Any insight or suggestions? Could a problem with the low fuel sensor cause the check engine light to come on?