As air-fuel mixtures and fuel efficiency become more critical, wideband oxygen sensors are gradually replacing the original single-wire oxygen sensor. Single-wire sensors act as an on-off switch, using an abrupt change in voltage to signal a rich or lean mixture. The Bosch LSU 4.2 Wideband oxygen sensor gives a more linear response, accurately measuring mixtures as rich as 9.0:1 and as lean as pure air.
This heated, 5-wire Wideband Bosch oxygen sensor (LSU 4.2) is the same sensor as supplied with the LM-2 Wideband Air/Fuel Ratio Meter Kit, Part No. 3878-001. (The Innovate MTX line of dash-mount gauges use a different sensor.) Standard 18x1.5mm thread.