I accidentally found this while reading an online forum, from what I've been reading this thing works like it's supposed to and is extremely accurate. Plus it's easy to install, just plugs into your OBCII port. For $169 shipped (159 on E-Bay) it's a pretty good deal.
Lee
-------------- ScanGauge II
DIGITAL GAUGES Display 4 gauges at a time from the 12 built-in digital gauges. the information is presented in Real-time! a.. Fuel Economy b.. Fuel Rate c.. Battery Voltage d.. Coolant Temperature e.. Intake Air Temperature f.. Engine Speed (RPM) g.. Vehicle speed (MPH) h.. Manifold Pressure (not available on some vehicles) i.. Engine Load j.. Throttle Position k.. Ignition Timing l.. Open/Closed Loop
SCAN TOOL The ScanGaugeII allows you to troubleshoot your own car, read error codes, and the conditions present when the error occurred. You can also turn off the "Check Engine" light and avoid those costly trips to the mechanic. a.. Reads Trouble Codes b.. Reads conditions that set the Trouble Code c.. Clears Trouble Codes d.. Turns off the "Check Engine" light e.. Tells you when vehicle is "Ready" to pass OBDII testing f.. Make and store up to 10 rewritable special codes to send to the vehicle computer