not communicating means the tester isnt reading what its supposed to. ie: o2 sensors. o2 heaters ect. this is usually remidied by a drive cycle. a series of specific speed bringing the car to a stop then going again. once the drive cycle is complete the car can be tested. the drive you had coming to tn should have done that.
a tune is when a compny goes into the ecu and retunes the computer for more performance. at one time the o2 sensors were turned off to inc. power. this would result in a testor not being able to read the sensors and result in a fail.
emissions testing not communicating and obdII testors have nothing in common so while 1 may not communicate the other can. ie: the emission testor can read a fault code but the auto zone testor cant read the O2 sensors are turned off.
your failed sheet should have the parameters that couldnt be read. post those