zerosix

iTrader: (7)

I was wondering if anyone had some insight on our O2 sensors on our car re there function

I have replaced the O2 sensors that are located on my heaaders, there is a total of two O2 sensors, one forer each side of the header as they are split in three's. These O2 sensor's only has one wire.

I would like to know if our ECU reads off this to pull or to give fuel?

I have one more O2 sensor located behind my CAT that has 4 wires that i have not changed yet. would this be the main O2 sensor that sends readings to the ecu?

I have read somewhere that our ecu reads off the ECT/CTS untill operating temp, then after our engines are at operating temp the ecu reads off the MAF and the O2 sensors. Was wondering if I should change the O2 sensor with the 4 wires

any help would be great

Gspec

What is the problem you're having? The ecu make fine corrections via the o2 data, but not so much as to keep it from running.

zerosix

iTrader: (7)

i am not having any problems as far as running..

Muy problem is i do not know which O2 sensor the ECU is reading the data from.

Is it the two O2 sensors on the headers or the O2 sensor behind the cat that the ECU reads data from to make corrections to the fuel and air ratio

booja

iTrader: (1)

its usually the primary o2 sensor... the one by the header.

i did not have my primary hooked up on my 2jzgte and had the ecu reset and my car would not run at right at all. it would go up and down at idle and if i blipped the throttle it would die. it ran super rich all the time.

got the primary wired in and hooked up and started and idled perfect.

Ali SC3

iTrader: (10)

the front 2 that are each paired to the 3 cylinders controls the fuel for the bank it is on.
the rear one is not used for fueling, its for emissions.

philauldridge

The previous post is correct. The rear 02 sensor is there strictly as a "tattle-tale" in case the cat. is not doing its job. The second pair of wires provides power for a heator resistor to get the sensor up to operating temperature pronto. This sensor has absolutely no effect on engine operation nor fuel management. If it senses a rich fuel mixture, it will cause the ECU to throw off a Diagnostic Code and set the Check Engine light.

Unless you're in an emissions-inspection state or region, many people just eliminate that rear sensor with an O2 simulator, which "tricks" the ECU into thinking all's well with the cat.

I've had good luck with a simulator from www.voodooboost.com (no direct connection with these guys)