The K&N Air/Fuel Monitor is designed to help with jetting or injector settings on any engine running on unleaded gasoline, alcohol, propane or nitrous oxide. The 3-color LED gauge displays your engine's air-fuel ratio from Lean to Rich.
This round in-dash unit mounts in a two inch hole like any standard guage for a permanent, professional appearance. This complete kit includes an oxygen sensor, weld-in threaded bung, and blanking plug (for running without the sensor). If your vehicle is already equipped with a one-wire oxygen sensor, you can just tap into the existing sensor wire rather than installing a separate sensor. This is the rectangular "surface-mount" gauge only; sensor and fittings sold separately.