Can someone tell me what wires are for what.

its a 3 wire Lamba, wire colours red, white , black.

signal, heater etc,, which is which please.

 

Red is +12v supply to sensor (heater) from main relay when ignition on
Black is Ground
White is signal O/P from sensor to ECU
Kevin

 

many thanks mate.

 

Just a little extra. There are two types of lambda, Zirconia and Titania. Zirconia usually has two white wires for the heater and one black wire for the signal. Titania has a black signal wire, a red heater 12v wire and a white heater ground wire. My MY00 car has a sensor with two white and one black wire (signal). Some earlier Subarus had the Zirconia sensor with a red heater 12v wire, a black heater ground wire and a white signal wire as I put in my previous post.
In all cases it doesn't matter which way round you connect the heater wires, the signal of course is very important. What is common to all the sensors is that the signal wire should have a gold plated connector pin.
Kevin

 

Can anyone help me out then?

I've got a 1995, and the standard wires are RED, WHITE and BLACK iirc.

I've just bought a Bosch Universal Lambda, which has 2 white wires and a black wire.

Which wires from the universal sensor do I connect to which wires on the OE connector block?

 

White on the original wiring to black on the Bosch and it doesn't matter which way round the other two are connected.

 

Is this correct C Maguire?

 

Yes, turns out Steve has a 1995 wrx same as you so my first post is right.
On the new lambda the black wire will be the signal and the two white wires for the heater (as polarity is unimportant they are both white). On your old lambda the white wire is signal (pin in connector should be gold plated), red +12v and black ground.
Kevin

 

So like this:

OLD...........NEW
Red ----- White
Black --- White
White --- Black

???

 

Yes
Kevin

 

Top man - i hope this helps others

 

I've fitted mine exactly as described in this post and it works a treat!