Lambda Probes 3 wire 4 wire

Does anyone know if four wire lambda probes will work on an earlier disco V8 with 3 wires, or can they be altered? any siggestions would be great thanks

yes they will, the fourth wire is for the heater inside the sensor, 3 wire sensors are not heated. you'll have to work out what wires do what before you fit them though.

Its not that simple,it depends what 4 wire sensors you want to use.If you are trying to use 4 wire ones for a 95-99 RR then it wont work as they are 5-0v Titania ones and the ones on your disco are 0-1v Zirconia ones.They are both heated types.

disco mart said:

Does anyone know if four wire lambda probes will work on an earlier disco V8 with 3 wires, or can they be altered? any siggestions would be great thanks

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Thanks for your help but how can i tell if i have the 5v variety?

LAMBDA SENSORS.

TWO TYPES, ZIRCONIA AND TITANIA.

ZIRCONIA, The most common type which produces a voltage, a low voltage indicates a high oxygen content and a lean mixture, a high voltage indicates a low oxygen content and a rich mixture.
This information is sent to the electronic control unit which constantly adjusts the fuel accordingly, ECU.

IDENTIFICATION: Fistly identify the number of wires on the sensor there wil be a choice of either, one, two, three or four wires options, the wires could be coloured as follows.

One wire, Signal wire. Black.
Two wire, Signal wire. Black.
Earth wire. Grey or white.
Three wire, Signal wire. Black.
2 Heater. White.
Four wire. Signal wire Black
2 Heater White
1 Earth Grey.

The thread size is 18 m/m.

TITANIA, The ECU supplies the sensor with a ref voltage, the resistance is measured, when the exhaust gases contain excess oxygen (the engine is running lean) the resistance is high. When the exhaust gases has little or no oxygen( the engine is running rich) the resistance is low. Titaniun sensors fall into two catagories the first as three wires;

One Wire Heater Postive Red.
Second Wire Heater Ground White
Third Wire Signal Output Black

Could also have a fouth wire.
Fouth wire Refrence voltage Yellow

The thread size is 12 m/m.


Hope this helps

Thanks for that, I am building a replacement EFI system from odds and sods this has been very useful