OBD Diagnostics Fail

[Vitalizm]

I borrowed a obd2 diagnostics software and hardware unit to see if there are any issues with my 08 highlander.

Everything seems to turn out ok except i get a few failed results. There are no check engine light or error lights on the dash or any pending or current trouble codes (in the diagnostics software). As far as I can tell everything seems to be running smoothly and I get at least the epa rated gas mileage. Is this something that I should be concerned about?

[AVConsult]

Different manufacturers use different emissions techniques and systems. The OBDII scanner accommodates most or all the codes, regardless of implementation. Therefore although the scanner polls the code, it may not be used. The code may be set to 00, FF, some random value or just return an error. If the ECU thinks it is not an issue, then so should you.