Originally Posted by DailyDrive

see, you haven't even seen an ODBII reader. you might have seen ODBII code readers.

An ODBII reader will show values right on the screen that the ECU sees coming off the TPS. All you do is hook it up, slowly press the gas pedal and look at the values the TPS is sending back. This test actually takes about 10 seconds to perform, if not counting the time to hook up the ODBII reader.