Na as nezinau ko cia visi staiga puole keistis liamdu is 3 laidu i keturis...Nes ne is taves vieno jau girdziu:)Siaip kalbejau su elektriku,tai sake kad veiks ir ta papildoma minusa tiesiai i variklio korpusa prisukus...Bet is esmes tuo ketvirtu laidu kazkaip pats ECU valdo ta minusa.Kam ir kodel nezinau... O geriau pasakyk koks tolkas is tokio keitimo is 3 i 4 laidus?

viskas labai paprasta, tik aš geriau gal pacituosiu:
Two or four wire Lambda sensors have an extra ground path down one of the wires. There can be a surprising amount of voltage difference between earth points on a car, and supplying 0v through a separate wire reduces the amount of noise in the signal, caused by for example rusty manifold bolts or poor engine earth connections.
Savo konkrečiu atveju keičiu tik dėl to, kad prisiskaičiau, kad amerikonai yra labai patenkinti juntamai sumažėjusiom kuro sąnaudom.....
matyt tikrai tikslaiu veikia 
Na tuo pačiu dar ir apie 5 laidų:
A Five-wire sensor is identified as a wideband sensor, and normally the harness plug has one or two spare pins (seven pins in total). The extra wires of the wideband sensor are used to supply a bias voltage to a chemical device known as andoxygen pump', which modifies the behaviour of the Zirconia element and provides a much more accurate measure of exhaust gas O2 content.