Moarpower

hey guys. So i followed the intructions on lexls's site only to find that the o2 sensors on my car are 1 wire not 4! I purchased the ones linked and listed as the right ones for my car my they have 4 wires. Will I be able to just use the signal while and cancel the other 3?

Yamae

No. You only can cancel 2 wires for the heater. Rest of 2 wires for the sensor should be used connecting the hot side to the O2 sensor line and the cold side to the engine body. It would be better to connect it to the E1 line of the ECU to minimize the interferences though.

Moarpower

Bummer. I was hoping to be able to use them on the pre cat sensors as they are only 1 wire and ground through the vehicle body.

if I ground the other wire somewhere on the body under the car should it work?

Yamae

It works well if the impedance between the body and the E1 line is low enough. Actually I have used many 4 wires O2 sensors for many different cars which were installed 1 wire O2 sensors originally. Some showed better gas-mileage connecting the cold side to the ECU's signal ground line directly.

As you observe the signal of a single wire O2 sensor line using an oscilloscope at the ECU side, you can see quite a lot of noise from ignition, injectors and others. So it is a good chance to improve the engine performance to use a 2 wires (No heater but has a separate ground wire) or 4 wires one grounding the cold side directly to the ECU's signal ground.

Moarpower

Thanks mate. I will see how I go grounding them in that way. If I can't figure it out I will just find a good ground to the body

Moarpower

Any idea of how I could ground these to the ECU ground line?