if the systems “aren’t ready”, theres nothing a computer is going to help you do…the systems haven’t reset yet. EVAP and catalysts are always the last to reset due to their function, but 500 miles is a bit steep. stop into any auto place that does inspections and ask for the “what do you mean my car isnt ready” folder, as it lists the proper steps for resetting “most” vehicles if the system doesn’t ready itself before then.
if the CEL was on before, and now its off but your cat and evap systems aren’t reset, you really can’t “trick” the system, which was designed to keep tards like you from doing so 
if the CEL trips back on…well…do the smart thing and have it scanned then to see what the problem is. if its an evap code, try replacing the gas cap first and then re-test the system. if it shows a cat code, have fun b/c aleros have either 2 or 3 o2 sensors (depending on the motor), which aren’t cheap either
yay for nys new inspection machines
:lolham: