I've been battling a P0455 Evap system leak error code for a couple of weeks. I usually get 4 to 5 days of driving back and forth to work (22 miles one way) between repair attempts with code reset and the next appearance. The CEL usually appears within a mile of home on a cold engine when it happens. I've replaced the gas cap and have found a couple of cracked hoses that have been replaced. I think I've covered the hoses under the hood well so my next attempt will be to drop the tank and check around there. I've dropped the back of the tank once and found a cracked hose to the carbon canister with the help of a small mirror. It's replaced. I think it's time for a more thorough investigation there. My questions are, is it normal for it to take a few cycles before the system checks for leaks ? Does this time frame point to any one component over the others so that I can start there once I've dropped the tank ? Thanks for the advice.