What is a wideband lambda?

What is a wideband lambda and what is it for?

The task of a lambda probe is to keep track of the amount of oxygen that the exhaust gases consist of. By finding this out, the engine management can calculate whether the engine is running rich or lean and then compensate for it. A small-band lambda, which is in most cars, can only measure if the engine is running rich or lean. A wideband lambda, on the other hand, can measure how rich or how lean it is. So you can say that they do the same thing, but wideband lambda can measure a larger area.

We use this when we tune engines. Then it is much more important to know the exact amount in order to compensate for it. So it is not enough to know which side of lambda 1.0 we are on, but how far from there.

When looking for maximum power from a car, you aim for 0.82 (12.4:1). It is the most efficient mixture of air and fuel. 1.0 (14.6:1) is what the inspection wants you to show, but it is in fact a slightly lean mixture. This however, produces the least emissions.

And while this is so important to see, it is not possible to be completely safe without a wideband lambda. Therefore, it is one of the most important instruments we have to check that the engine is running properly.

What is the difference between AFR and LAMBDA?
There are 2 different ways to read a lambda probe. Lambda is measured as 1.0 when AFR is 14.6:1. It's simply just two ways of saying the same thing.