Lambda sensor

[SKINNYSEAND]

Hi guys,

Just want to know how easy is it to change a lambda sensor.

[chrisop]

you can do it yourself but they can be a bit hard to get at. i have only took one out of a passat in the scrap yard. the actual sensor was easy to get at- although the air filter, i think was removed from the car. the hardest bit was getting the wiring disconnected and fed through the clips. i am sure someone will be along soon to give better advice

[SKINNYSEAND]

Thanks Chrisop. I am now trying to find where the wires lead to so I can unplug it.

[martin1810]

The lambda wires should lead to a four pin black plug which you disconnect. You should be able to read lambda values through vag-com but I'm not sure if all versions can. Ross-tech site may tell you which measuring blocks. If you send me an e-mail address I may be able to send some info. Goodluck

[SKINNYSEAND]

I read the values. They usually start off at around 21.2% then it rapidly goes to 0.0% then it starts juddering and losing power.

[martin1810]

Sounds like you need a new lambda sensor. If you can scope it you will see the voltage oscilating up and down like a switch going on and off. It must clear a high point and a low point on each cycle and manage a fixed number of cycles per minute.