Lambda Probe Wiring

if there is a STOCK chip fitted you are correct.

if you want to find out, disconnect the Lambda probe. Attach the signal wire to a multimeter (Lambda probe does NOT need to be connected to the car for this, it's only the heater which requires power)
Set Voltmeter to 1V and drive the car with STEADY throttle. Let somebody watch the Multimeter (but drive for at least 5 mins to get the sensor heater).
If the Volt reading fluctuate up and down steadily (down to almost 0.2 V) your Lambda control is ON.
If the reading is quite "calm" your Lambda control is OFF.
This is also a good method to test a Lambda Sensor

Edited by UweM3

hoggr wrote: Thanks Uwe. Do you mean using a multimeter between the signal wire on the wiring loom side and earth (body of the car)? Or do you mean the signal wire from the actual lambda probe and earth? And which of the three wires is that? Which colouring? Rob.

just the signal wire to the + of your Multimeter and Multimeter - on Ground.
Can't remember the colors but the 2 white ones are the sensor heating, so what ever is left if the signal (think it's black)