Lambda sensor-easy to take out and inspect and then put back in?

[itavaltalainen]

the colours for original vw i got straight from vw software....
should be correct

of course engine needs to be running, how else would the sensor work? should work quite quickly after starting... 10 minutes - in lapland in winter maybe in current weather after a mile it will be already (near enough) operational temp.

[Jasikasisback]

I apologise for being so dumb. Anyway I don't want to damage any of the wires by exposing them or remove the O2 sensor (if I don't have to). The only test I have figured out that I can do is the following:

1. Unplug the sensor as I will probably burn myself trying to get it off once the car is running and hot. Tie the sensor to the fuel lines with tie so it wont be damaged and I can easily access the exposed pins.
2. Drive around for about 10 min or so to warm up the O2 sensor to operating temperature.
3. Take the multimeter and attach the black probe to the car as to act as the ground. Attach the red to the signal wire pin on the sensor plug which is yellow or white (depending on the plug I guess-wont hurt to try either anyway)  This will give me some sort of value between 0-1.0V I hope.
4. Rev the car and see if the voltage fluctuates. As I rev it by pulling the throttle cable the voltage should go up and then go down after I stop revving. (inversely mirroring the amount of oxygen available)

In this way I don't have to remove anything and the risk of damaging anything will be minimal. This will at least tell me that the O2 sensor is working? I think I will be able to tell if the O2 sensor is sluggish or not and if the voltage goes up and down then at least it is working for now.

Does that all make sense or am I just spewing rubbish..

Also I could possibly just hook it up to the ground wire in the plug to make sure the ground wire is functioning. (brown?) Maybe best to just ground the multimeter to the car.

Guess I wont really damage the car if I drive for 5-10mins without the O2 sensor on.

I would replace it but as it costs around £60-70 new. It will be hard finding an auto lambda in the scrapyards and as far as I know the AAM engine doesn't really share this sensor with other models/engines..

If this sounds like a good plan then I will give it a go tomorrow.

[itavaltalainen]

you can do it the way described. but it could be that the lambda then does not change voltage as the ecu will detect its disconnected and run in rich mode to prevent damage. could be that this is outside of normal operating voltage of the sensor and it will not change value.

will check if there is another point where you could check the voltage from..... maybe easier to get to the pins at ecu?

on ecu its pin 15 (white) and 38 (yellow)

[Jasikasisback]

I've never touched' the ECU. Afraid i Will damage it.

[itavaltalainen]

just get vcds (lite) already...

you can check all this kinda stuff in their without mucking about with wiring.

pins at ecu are not too bad to get a hold off.

[Jasikasisback]

yeah you are right.