I did try replacing the gas cap and after everthing I did replace, in short, it turned out to be the seal between the air canister and the airfilter box under the hood. Instead of 100 miles for the readiness sensors to be ok, it only took about 50-60 after I sealed it with a big bead of silicone... I know this is not likely to be the cause of other peoples problems, but WAS the cause of mine and posted because no information was mentioned about it anywhere else.