No need to re-invent the wheel!...since the Scangauge does all that....
Plugs into the OBD2 port; X-Gauge function has the ability to query all CAN outputs if you can come up with the Hex codes. The Z runs CANSF mode on the scangauge which has a fair number if data points documented and accessible..While I have seen these kinds of modifications to existing screens done on other cars (the EFU for Audis being one example), it generally takes a brand enthusiast who is highly skilled (and motivated) and if it ever hits the market( 4 years in the case of the Audi), very expensive...I wouldn't hold my breath on this!
OBD is open source though, so knock yourself out!....:-)
On-board diagnostics - Wikipedia, the free encyclopedia
Info available that I can pull up on mine (any 4 at once):
TPS: Throttle position sensor 0-100%
fIA: Intake Air Temps (Temperatures at the intake manifold)
fWT: Coolant water temperature
HPR: Horsepower (Looks to be pretty accurate from initial runs on several cars)
VLT: System Voltage
IGT: Ignition timing (advance)
LOD: % Power request
Closed/Open loop: Fuel management and transition point from O2 control to WOT
STF: Short term Fuel trims
LTF: Long term Fuel trims
OX1: #1 O2 sensor output, 0-100
OX2: #2 O2 sensor output, 0-100
MPH: Digital speed reading from Speed sensor
RPM: Digital RPM’s
MPG: Miles per gallon
GPH: Gallons per hour
Trip Data: Fuel economy, Fuel used, Distance, drive time, Avg. speed,
Distance/time/fuel to empty, ETC.
As a Scan Tool It can act as a Code reader and eraser,Determine Readiness tests, Turn off and clear CEL’s etc.
ScanGaugeII - Trip Computers + Digital Gauges + Scan Tool
I generally keep Water temp, Intake temp and short and long term fuel trims up on mine all the time.. Handy tool!