Just put a new battery in and need to fix a P0455(medium evap leak), but it's been 300 miles and the evap readiness state is still incomplete.. Anyone else came across this? Google only comes up with the same force-completion generic routine as answers and the routine doesn't work.

I tighten the gas cap every fill-up, keep tank at least 1/4, and have checked all the under-body and engine-bay lines for cracks. I haven't replaced the $40 purge canister by the passenger headlight, or the charcoal canister under the drivers side of the body. I also haven't had a smoke test done. Dealerships and part houses seem to spike prices for SAE hoses and things around evap systems, and smoke tests cost at least $100.00..

UPDATE: Finally got it to finish, cranking and letting it idle for 5min before drives may have helped, but I'm not certain. Would love to know the real drive cycles..