Consider this scenario:
- The CEL (check-engine light) is on.
- The fuel cap is subsequently replaced.
- The fuel tank is half full.
I am wondering:
- Is it advantageous to fill the tank to the top to speed up the time it will take the CEL to go off? (we assume here that the fuel cap is the culprit)
- Whether the answer to (1) is yes/no, after how many miles does the CEL typically go off? Or does the air vaccuum mechanism on the fuel tank operate every so many minutes, and so it's the driving time, not distance, that matters?
- Once the CEL is no longer on, does the mechanic disadvantage the vehicle on the bi-annual report? In other words, is one better off reading the old codes with an OBDII reader and clearing them?