I've been dealing w/ this CEL the ENTIRE time I've owned my Subie. Taken it into the dealership 15+ times and they can never do anything for me. I bought a new gas cap, checked my lines and finally learned to live with it and bought a bluetooth OBD II sensor so I can turn off the CEL myself. Hopefully yours is an easy fix. If you find what the issue is on your car will you LMK?