ELM327 OBD2 Bluetooth car scanner

Display current sensor data, including:

Engine RPM

Calculated Load Value

Coolant Temperature

Fuel System Status

Vehicle Speed

Short Term Fuel Trim

Long Term Fuel Trim

Intake Manifold Pressure

Timing Advance

Intake Air Temperature

Air Flow Rate

Absolute Throttle Position

Oxygen sensor voltages/associated short term fuel trims

Fuel System status

Fuel Pressure

Exhaust gas temperature 

Many others...