2008 Chevy 2500HD DIC "Check engine"
 

I recently removed my external fuel tank, and forgot to plug the hole where it piped into my fuel tube. A day later a warning message popped up. I stopped driving it. I haven't come up with a good plan for sealing that hole. Anyhow, could that air leak be causing my truck to throw that "Check engine" message? Thank you

do you know what code it is?

I've not had it scanned yet. To be honest, I'm nervous about driving it and causing more problems. But unfortunately I'll have to do that at some point. Thank you for responding, I'll post more information when I can.