I kept getting a check engine light and the fault code 'Evaporative purge flow implausible ' or something like that. It was only every now and then, so it was easy to clear, just annoying. I knew that the cambelt had been changed by a gorilla before I bought it, and the purge valve had been glued back together. I finally got round to replacing it a month back, before a trip to Bavaria.
The check engine light hasn't come back since. The valve was all of 12€ from the dealer. I should have done it five years ago.