Truck had code PO442 which was a small line with a crack in it off of the evap canister. That was last year now I am getting code po455 as a gross leak. I dd a quik visual inspection of the rest of the rubber lines on the canister didn't really see anything. What are the chances it is the gas cap? It is an '03 so the cap is 10 years old.

 

http://wiki.answers.com/Q/How_do_you...ine_code_PO455

 

OK I disconnected the negative battery terminal, removed the gas cap and put it back on. Re connected the battery. Check engine light is off and has been for a week. Checked it with a code reader yesterday which read no codes.