A variation on the zirconia sensor, called the "wideband" sensor, was introduced by Robert Bosch in 1994 but is (as of 2006) used in only a few vehicles (such as the Subaru Impreza WRX when equipped with a manual transmission). It is based on a planar zirconia element, but also incorporates an electrochemical gas pump. An electronic circuit containing a feedback loop controls the gas pump current to keep the output of the electrochemical cell constant, so that the pump current directly indicates the oxygen content of the exhaust gas. This sensor eliminates the lean-rich cycling inherent in narrow-band sensors, allowing the control unit to adjust the fuel delivery and ignition timing of the engine much more rapidly. In the automotive industry this sensor is also called a UEGO (for Universal Exhaust Gas Oxygen) sensor. UEGO sensors are also commonly used in aftermarket dyno tuning and high-performance driver air-fuel display equipment. The wideband zirconia sensor is used in stratified fuel injection systems, and can now also be used in diesel engines to satisfy the forthcoming EURO and ULEV emission limits.

Wideband sensors have three elements:

Ion Oxygen pump
Narrowband zirconia sensor
Heating element
The wiring diagram for the wideband sensor typically has six wires:

resistive heating element (two wires)
sensor
pump
calibration resistor
common

Can the WB sensor be used with leaded race gas?

How about Methenol/Ethenol?

The 49-State lean burn Honda Civic VX (1994-1995 I believe) used a wide band O2 sensor, but I don't know if it's of the proper type to use with the aftermarket controllers and readouts.