Trouble code P0703 means:Torque converter/brake switch B circuit malfunction
Trouble code P0463 means:Fuel level sensor circuit high input
Trouble code P0461 means:Fuel level sensor circuit range/performance
Trouble code P1326 means: ION Sensing Module Combustion Quality
Intake Throttle Position Sensor High Voltage
PO341 Camshaft Position Sensor Circuit Range Problem
The ASR dash light is a brake assist system/acceleration slip regulation light. When this light comes on in the Isuzu NPR truck, the on board computer in the vehicle detected a malfunction in the acceleration slip regulation and the vehicle needs to be taken for service.
Diagnostic trouble code
Trouble code P0562 means:System voltage low
Trouble code P0442 means: Evaporative Emission System Leak Detected (small leak)
Trouble code P0507 means:Idle control system RPM higher than expected
Well I just checked about 6 sites that list Isuzu specific obd2 codes. Problem is, not a single one of them list that code. Are you sure it's the right code? If it is, you're probably going to have to ask a dealer or mechanic. If you mean P0128 that's a thermostat insufficicent temp and it req's a t-stat
Engine is running rich