u/Aggravating_Button99

My 23 TB has been intermittently showing a check engine light.

First time I had scheduled a tire swap/oil change in a couple says and was going to get it read, but it went out the say before. That was a month ago.

Last week it was on again but since the last time where it disappeared I left it . 2 days later it is gone.

Today I drove somewhere and when I filled with gas, it came back. Suspected gas cap, so took off and put back on with no fix. Drove several places and on way home its gone again?

Is this a gas cap issue? How to test it, or is there a way to fix without having to get a cap that may not fix?

Is there a cheap reader I could get to scan it?

Thanks all