Hi all. First post here, be kind. My 2008 CLK 350 convertible is not passing emissions testing and I'm completely frustrated! Code showing is P2422. Charcoal cannister was replaced along with the solenoid, but I'm thinking I need to replace the purge valve. Input? Where is the damn thing (purge valve) located, what part number do I need, is it an easy fix for a non mechanic...what are your thoughts? Truly grateful for the info!