http://www.scangauge.com/
My review:The Ultra Compact 3-in-one Automotive Computer
Scan Tool - Trip Computer - Digital Gauges
The integrated Trip Computer provides realtime feedback while simultaneously tracking three sets of trip data. The Digital Gauges give you realtime data for your vehicle and the built-in Scan Tool allows you to read trouble codes and diagnose potentially expensive problems before they get out of hand.
A few weeks back I happened upon a group buy (RPM) on LegacyGT.com for the Scan Gauge II (SG2). The price that they offered was the same as retail $160, with free shipping, and if 35+ people ordered we got a discount. When the group buy ended, I had a scanner for $140.
The SG2 is well constructed, and comes with a long (6 ft) cable that hooks into any OBD2 port. The unit itself has two positions for the RJ45 (ethernet type) plug, one on the side, and one in the back. This gives you a few options as how to mount it in the car. The OBD plug is also nicely made, with a right angle, so it's not jutting out weirdly.
The scanner works by interfacing with the ECU - so it'll only show the information that is readable by the ECU - if you have a sensor out (or not installed) then it won't show a reading on the scanner. For example, my speed sensor sometimes cuts out, which means my SG2 will read MPH as being 0, even though my tach will still read 2500rpm.
One thing I did find out though, is that BD/BG cars have a finicky OBD protocol - you have to set the SG2 up to read only "SUPPORTED" protocols, not "ALL". This is noted in the manual, which is quite detailed.
Until I had set the protocol to "SUPPORTED", my SG2 would switch off every 5 seconds, and refused to clear my CELs. Once I switched protocols (easily done via the mode buttons) things were all good.
Some of the nifty readouts I like using - volts, MAP, TPS and IGN.
Manifold Absolute Pressure
Throttle Position Sensor
Ignition timing
(I don't know exactly what the differing values mean, but I know what they values should be when the car is running properly LOL)
One of the coolest functions that this thing does, is you can change the color of the display. Right now I have it to match the green of the Legacy dash lights.
For the money spent, and considering that an Actron Scanner costs about the same - you get a whole lot of useful stuff with the SG2, that you don't get anywhere else. You could also work out a custom mounting solution for it, and it works in other cars as well (I just recently used it to diagnose a 2002 Pontiac Sunfire, a 2001 Ford F350 and a 97 Chevy Astro).
The SG2 gets a big thumbs up from me, and I'm pretty darn picky.