Lifeforce

Hi guys. Got a re-occurring code on the 09 c63. Keeps giving me p0455 - Large evap leak detected, and also a few times a day I get the gas light flashing and the error message the gas cap is loose.

A few weeks ago I replaced the purge valve and the gas cap. All new dealer parts as well. Still having the same issues. Also when I rev the car it just doesn't sound as loud as a few days ago and it seems to stumble when I rev it in idle above 3500 rpm, it's odd. Went to start it tonight after I reset the CEL again and it started but died shortly after. Restarted it and was fine. Maybe CPS?

Car still drives like a bat outta hell though. To include, the car has MHP longtube catless headers, ecu tune, and charcoal delete. Would the charcoal delete cause the CEL? Maybe bad charcoal canister itself??

Mort

No direct experience here but if the gas cap and purge valve have been replaced and are operating properly then a check of the evap lines from the tank to the engine might show a broken or disconnected line. Also you might check that the evap canister is not flooded by overfilling the tank.

Merc63

Check the evap lines

Lifeforce

What's the best way to clean the evap canister? It's located on the passenger side by the filler neck correct?

Mort

The evap canister is by the filler neck. Not sure if it can be cleaned if it is full of gas. Hopefully someone else can help you out with that.