Q: Do I need to turn the gas cap so hard that it clicks repeatedly.
A: Different gas caps require different procedures. However, many vehicles today require the gas cap to click at least three times. If the gas cap is not installed properly, the “check engine light” can go on. An improperly tightened gas cap could allow excess fuel vapors to evaporate and enter the atmosphere. Gasoline vapors contribute to smog. The best advice I can give is to check your owner’s manual or to see if the gas cap itself has any writing on the top of it that identifies the procedure.