Few months ago, the check engine light was on in my 2010 Fusion 2.5l (capless fuel tank) due to evap leak. Pepboys changed the 'vapor can vent sol', 'vapor can purge sol', and 'O2 sensor'; costing me over $900! Again, the check engine light is ON for evap leak recently. I went to PepBoys and they estimated $400 to solve it (saying to change another valve...!!). I have a hard start after refueling. 1 or 2 times the check engine light had gone automatically and again came back after couple of days. The vehicle runs smoothly and no drop in mpg. I cleaned the gas cap and, I will do the vacuum check of purge valve. My two quick questions for you are:

1. what valve is needed to be change costing $400 other than already did two by Pepboys?
2. If I keep driving like this, will it lead to any other costly damage?

 

We need a little history before suggesting replacing anything.

Are you in the habit of filling your fuel tank until it will not take anymore ?

 

No, never. I always use automatic fill. Additionally, my habit is top it full when fuel signal comes on.

 

Good,
The reason I ask this is , the evap system in most vehicles today is designed to handle gasoline vapor only.
When liquid fuel gets into the vapor only parts the charcoal material starts moving into the lines and components of the evap system and interferes with their function and hence the evap codes.
Some of those valves have filters that draw in out side air and they can become restricted and require replacement. Most are electrically controlled by the vehicle computer and the electrical portion can work but the actual operation of the valve needs to be verified as functioning physically, and can require time and work

Hope this little bit of info will answer some questions. When the nozzle shuts off , the tank should be full , no need to add any extra.