2009 Kia Rio - CEL and clunk

Check engine light is on and off for the last 2 weeks and when I back up there is a big clunck noise and when in drive to start hesitation

That is telling you there is an error somewhere in the engine that needs correcting. A mechaic can read the error codes to help diagnose the problem.

May be related, probably not. Either way you need to take it in for service soon.