good to know .. I had no idea
When I drove my brother's Pontiac Vibe car, I didn't tighten the gas cap as much as I should have and a light on the dashboard came on. I didn't remember exactly which one it was (service engine? picture of gaspump? something?) I had to read through the service manual to find out possible reasons and finally found the loosened gas cap to be the reason. After I filled up a couple times after that, the light went away (as did my anxiety about that stupid light, lol!) I didn't even realize that was an issue or option on the dashboard on some cars to remind you to tighten it.