07 Forester X

I have error code P0456 - system malfunction or small leak. This developed about the same time as my cruise control stopped working.

Check engine light is on, and "Cruise" keeps blinking.
Could these problem be related?

Any ideas on where to start looking for a SMALL leak?

My Harbor Freight code reader also shows code P0456P. Does this extra P have any significance?

27,000 mi and 3 months out of warranty.

Thanks

Tony