Engine codes on my c280
P0442 - Evaporative Emission Control System Leak Detected (small leak)
P0455 - Evap System Large Leak Detected
P0170 - Fuel Trim Malfunction (Bank 1)
P0173 - Fuel Trim Malfunction (Bank 2)
I cleaned the area around the gas cap to ensure a tight seal and then disconnected the negative battery terminal to clear the code. Today the check engine light came back on.
I have also listened under the hood for a vacuum leak and haven't heard anything. What should I do next?


