How to tell when OBD II monitors are cleared?
I recently bought an '04 4.7 GC. The former owner had just returned from
Smog Check with a "failed the MIL/Check Engine Light due to failure to
successfully complete all OBD self tests."
As explained by the smog tech, the vehicle had just undergone some service
that had cleared the codes, therefore the vehicle should be driven for "about
80 miles to reset the monitors. Since I was 100 miles from the original
test station, the tech suggested that I ask the next tech to make sure the
monitors had been cleared prior to the smog recheck. I did so, only to be
informed by this new tech that it was illegal to check the monitors prior to
running the smog check. So, my question is; how do you check to see if
the monitors are clear? I have access to a Mac Tools Global OBDII Scan
Tool Mod#ET9620. Can I check the monitor with this tool?