my cap clicks sometimes when it's not all the way tight. I have to steadily turn it slowly, then it spins loosely a bit more and tightens for real.

 

^^i had the same issue last week, i started smelling gas when i would stop and turn the car off. The next time i filled up, i realized the cap wasnt fully on. I made sure to tighten it, and it felt loose, so i turned it again, and finally felt tight after a few more clicks, and i havent had the smell since. It didnt throw a code, but it worried me, especially since i just bought the car

 

Clicky clicky
Glad you got it fixed... mine is usually do to my damn Test Pipe after an HPDE or Boston Moutain tour.