To save some frustration for others who have also had an annoying gas cap warning message linger on and off for months even after replacing a gas cap. Then engine light to start coming on in conjunction. Found out it was a bad evap purge canister. Possibly due to topping off the gas after it clicks. So just something to keep in the back of your mind or check out if you are having the same issues. Not always the gas cap or a sensor.