Reevesms

So I just purchased a preowned 2007 GL450 with 88000 miles. The check engine light comes on and I take it to the dealer. After having it about a day, they find that it needs a new charcoal canister and shut off valve ($900 repair) (emissions). It ran fine and no light and started perfectly (before taking it in, it would not start half of the time). I get 1 mile from home and check engine light comes back on! I load my code reader and am getting a P0455. And yes, the car seems to have a fairly new gas cap and it was tightened to 4 clicks.

Any ideas would be appreciated.

sak335

You and another member seem to both be "frustrated" by the same problem:

https://mbworld.org/forums/gl-class-...rustrated.html

You may want to search before you post, rather than starting a new thread. You'll find some additional information in the thread above, but the short answer is that this can be a difficult problem to diagnose. I personally would be ripping the dealership a new one for throwing expensive parts at a problem without properly diagnosing the issue first.