O2 Sensor Question
 

Hey guys,

I'm running non-sequential setup with a PFC, and Zeitronix wideband. I'm running upgraded fueling system.I was doing some work on the car, and the wire to my O2 sensor broke off the tip of the sensor after I reassembled everything in the engine bay. Before I start taking everything apart, I thought I'd ask this question.

Do I need the O2 Sensor anymore? If I do, then do I need to buy the Mazda O2 sensor or are there generic ones that would do the same at a much lower cost?

Thanks
T

Does your PFC have O2 feedback on or off?

I have used both. The previous owner had the setting off likely because the sensor had failed. I replaced the O2 sensor and have tried both on & off. I've noticed no changes with either setting. The voltage readouts on the pfc indicate the sensor works properly.
It seems many people leave the setting off since it improves idling performance. However, I haven't seen those issues with it set ON either. Currently, I have it set ON.

From my understanding, the PFC uses the O2 sensor feedback to trim the fuel during idle and light cruise.

If your car is tuned, you don't need an o2 in your situation. You not noticing a difference with o2 feedback on or off is the correct result. I would say leave it off and get a plug for the o2 port on your downpipe.