For my OBD1 cars, I use WINALDL with homemade cable on an old compaq presario laptop. BUt for the GTP, I just use actron's simple autoscanner cp9575, it was aon sale for $99 a couple years ago and includes CAN also. I just used it today to view live data while driving down the road, seems that my #2, o2 sensor is lazy after 170,000 miles and throwing a p0420 once in a awhile.