Thanks for the info Joseph. The CEL is not on, also this problem seems to happen only after long idle time, wouldn?t a leak always cause a problem? Do all Autozone stores do this kind of diagnostics, or are there the ones that have service station (that is if such a concept exists in the first place). I live in Kalamazoo, MI which is a fairly small town. The Autozone closest to me definitely does not have a service station. Frankly a couple times that I have posted here, someone has asked me to the same but I have never had the audacity just to go to Autozone and say hey guys do this diagnostics for free. I guess I can just ask for a diagnostic and if they offer it for free great and if not just pay for it.