corvairbob

i have the 2000 2.2l 2wd s10 i got the p0442 code and did lots of repairs the code came back the other day so i have no idea if that was just a residual code that finally made it show. so i got a foxwell nt6x4 scanner and i cleared every code in the system that scanner found and sent 2 evap commands to the ecu. i sent one and then the next day drove it 10 mile round trip and then yesterday i sent another evap command and today i will drive it about 6 mile round trip. so what i need to know is does the evap run during off time or driving time? and how many times does the evap run the test before it will show a fault?
thanks