Woodhouse stocks them, call Nancy, she will overnight the correct cap. I had the same problem and could not get the check engine light to go away with the local purchases like pep boys etc. They don't seal correctly for emissions, Don't have any experience with the autozone cap. I had to wait 30 start cycles for the check engine light to go away. The gurus (JonB etc) do not recommend disconnecting the battery to reset for this one as it will go away by itself and you will not experience any drivability issues as the computer relearns.