Does clearing a DTC with the xcal2 reset the drive cycles on the PCM? Just curious.

 

The drive cycle is reset everytime you turn your vehicle off I thought.

What difference would resetting them with a tuner make.

 

If you're trying to clear a readiness code for emissions, you'll probably need to complete certain monitor tests while driving the car. Look at the driving cycle page here to get an idea of which things get completed under which conditions.

http://www.obdii.com/obdii.html

 

anytime that you clear the codes the drive cycle is also reset.each moniter will have to do its own drive cycle to test for codes.some tests will run on start up, other tests may days to complete because the car has meet exact driving conditions before the moniter will run.