Every car has at least one and we have never put attention to it. Time to change!
Don’t be afraid, I, the undersigned, will you this time do not get bored with a long technical story (example 1, example 2, example 3). There is much to be nice again. Instead you get a short and concise as possible article about this piece a little with a sexy name. To start with a short description of the task of the component. The probe is intended to be the fuel injection such that the catalyst optimally his work can do. That means less harmful substances that the exhaust exit.
For cars with one lambda sensor fitted about the gadget before the catalytic converter in the exhaust. The probe itself is a small cylinder of ceramics (see headerfoto) that only in the higher tempaturen works. The probe is also heated, because otherwise it makes the device little. The thing measures the difference in oxygen between the outside air and the exhaust gases. Depending on this so-called lambda value adjusts the engine management the relationship between the spray of fuel and air. The lambda sensor gives the signal to the ecu through electrical voltage or changing resistance.
Modern cars have one after the catalytic converter in an extra lambda that checks if the catalyst works well (enough). Depending on the mixture may also be adjusted. Everything for the cleaner exhaust gases, you’d think.
Finally: this was absolutely not a full explanation, there was the article not meant for that. It is more about that now you know approximately what is meant when talking about lambdasondes, to the extent that you did not know, of course.