I just installed a heated O2 and wanted to know where the best place to feed it from was,have heard people use the fuel pump relay but I don't want to loose any voltage to the fuel pump,what does the MAF burnoff draw for power?could I go to this?any better ideas?

 

I did the fuel pump relay method and have noticed no ill effects. I don't think so many people would do it and then recomend it to others if it hurt the fp's function. From what I understand, that circut has more than enough extra current to provide the minimum amount that would be needed for a heated element like this sensor has. Other options could easily be found with a multi-meter.

 

I have mine feeding off the fuel pump as well on my GTA. I use a little 6-volt relay wired into the AIR select valve to close the circuit and activate it. When the ecm energizes the air select valve (causing it to divert the air to the exhaust ports when the car is in open loop), it also activates the relay which in turn closes the heated oxygen sensor circuit and lets the o2 sensor heat up. When the car goes into closed loop, it de-energizes the air select valve to divert the air to the cat. this also de-activates the relay and turns off the oxygen sensor heater.