Wouldn't be caught dead without it....
One of the best things you can add to your car. It shows the O2 millivolts and KR continuously, plus will record the lowest O2 and the highest KR when you make a "run"...and show you at what mph they happened at.
You can file through all the data coming from the ALDL port which means TPS Volts, MAF gps, inlet air temp, coolant temp, BLM's, INT's, IAC#, O2 cross counts, etc.
John