OBD/Readiness Driving Procedure
bringin up a dead one again!!! you can do the drive cycle 10 times with your car sitting overnight every time, even with no pending, historic or logged faults & a seemingly/feeling fine running car & if a test or 2 or 3 don't run, they just wont until you get the car properly diagnosed as to why whatever tests aren't running or try some random ish. catalytic & 02 sensor heater are the worst. 500 miles & mine did not clear (those 2) ... swapped my GOOD denso passenger upstream (it was brand new & what made my cel & all faults clear & car idle perfect, replacing a bad ac delco) with a new ac delco and the 02 heater cleared in 3 miles & the catalytic in about 10. go figure - my brand new good denso fixed/allowed the car to run perfect yet wouldn't let those 2 codes clear.
