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  1. CEL Code 455 and 496

    Problems and Service
    Since last feb. when I got gas siphoned out of my tank my CEL has been coming on and usually staying on. The codes has been the following: PO455: EVAP System Leak PO496: EVAP High Purge Flow My MPG has gone down some. I went from mid 30's to upper 20's. Any ideas as to what the problem is...