The check engine light started showing up on my wife's 2004 Mercedes C240. I checked with an ODB tool and got the code mentioned in the description. After a quick Google search, I tightened the gas cap and cleared the code. Unfortunately, a few days later, the light is back on again.
After a quick search on MB forums, it seems that the problem is hard to diagnose but is typically solved by:
1) Replacing the gas cap
2) Replacing the purge control valve
3) Fuel tank
However, it is not guaranteed to be one of the above and is typically diagnosed with an expensive smoke machine.
I'm a bit overwhelmed by the lack of information available online and my unfamiliarity with how the evap system works. Should I throw some parts at the problem and hope it goes away? Or take the plunge and go to a good indy mechanic?
A third option is to try to make a "DIY Smoke Test Machine" as shown at https://youtube.com/watch?v=2U5kFib1WxE
I'm not a car expert but am just getting to the point where I'm comfortable handling routine maintenance on my cars such as Oil, Coolant, ATF and brake fluid changes. Apologize if this comes across as incoherent, I'm down with the flu and not thinking clearly.