Question

1999 Ford Explorer with Heated Oxygen Sensor, and EVAP codes. Fail inspection

Answer 1

Heated 02 , catalytic. and EVAP, all 3 would have to be from the monitor being incomplete, there was a trick that was performed just to get the monitor set and that was to replace the front 02 sensor, then the 02 monitor would run, when that was set the catalyst would run and last to run would be the EVAP monitor.