Anyone know how accurate the OEM PIDs/sensors (i.e., water temp, AIT off the MAF, oil pressure, etc)? I know the OEM gauges were dummied-down to basically sit in the middle of the scale, then turn red when things have already gone bad. But do the OEM sensors still communicate accurate info back to the PCM? For example, does the OEM water temp sensor transmit accurate water temp back to PCM, but the dummied-down OEM gauge won't display it.

Just wondering if I invest in an OBDII Scan Gauge (like PLX DM-200, Aeroforce Interceptor, MSD Dashhawk), will these devices be able to pick up accurate water temp, AIT, etc off the OBDII/CAN ? Not sure if I will be required to install new individual sensors and controllers to be able to read/display accurate info. I'll be putting in a separate wideband O2 sensor, controller, and gauge, but was hoping I could get other PIDs off the OBDII/CAN and display those through an iMFD multi-display gauge. Thx.

 

The PIDs will display GOOD results, but the network delay (IIRC the S197s use a CAN bus instead of the older PWM) is still pretty bad with OBD-II systems. The analog gauges aren't very precise, but the ECT PID will be accurate.

My speedometer is way off at higher speeds (reads about 2-5 MPH faster than GPS and the VSS PID).