I've been running a PLX AFR and have been very pleased with it and last week added the boost sensor module. The boost sensor module incorporates a 3-Bar Map Sensor.

Is the correct integration of this product to:

A) Leave the stock MAPSensor plugged in and run the PLX boost sensor off the additional nipple on the UIM

or

B) I unplug the stock MAP Sensor and run the vacuum hose the PLX Device?

Thank you for your help.

 

A) Leave the stock MAPSensor plugged in and run the PLX boost sensor off the additional nipple on the UIM

 

definitely A

The stock MAP/boost sensor sends signal directly to ECU to calculate fuel/timing ect.
The sensor you are adding is just for the PLX device to calculate boost/map reading for Gauge only. You can upgrade you factory boost sensor to a gm 3bar if you have a standalone ecu to reconfigure the new sensor.

 

You could try it but I don't think the ECM will interpret the 0-5V linear analog output the same as the 5 V bias at 1.3 to 4.6V it looks for from the MAP sensor. For example, at 0.0 kPa (0.0 inHg) the ECM is looking for 2.55 to 2.75 V where as the PLX analog value is around 1.6V for the same pressure.

The two scales are not the same...... If you had a PFC you could recurve to fit but with a stock ECM it wouldn't work.

Lastly, even if you could get it to work the Mazda ECM provides a very stable 5 volts to the MAP sensor so a good bias against ground can be returned. I wouldn't expect the rudimentry electronics in the PLX sensor modules to have a stable output..... With that said, however, I use the analog output from my PLX SM-AFR to feed the O2 narrow band back to my ECM and that works just fine.