Check engine light...........................

Does anyone know what the most common problem that might set off the check engine light?....I have a 2005 v6 w/60,000 miles on it. Lately the light will come on here and their. I may start the truck up and all is well......3 days later it will come on when I start the truck and run the whole time the truck is running. Then I may get out to go get something and come back and its off again?..... Anyone run into this?....Like I said,this is a hit and miss type situation............

 

Is your gas cap on tight?

 

Loose gas cap?
My mom always forgets to tighten it, and it throws a check engine light.

 

Gas cap is on tight..................and yes I will get the code read.....I was just picking your brains...............can a gas cap go bad?

 

This is happening on my dads F-150 the shop replaced the O2 sensor, but only fixed it for a week. I never can catch it with my scan guage.

 

Basically it like finding a needle in a haystack .....................I just wondered what might be the most common problem....

 

Autozone will read the code for free. I think most other places will too.

 

Don't forget................AAMCO