Specifications Electronic:No High-concerned chemical:None Type:Heating Type Hysteresis:For Mercury Mountaineer Linear:front Measuring Range:For Mazda Sensitivity:For Ford Sensor Type:Piezoelectric Origin:Mainland China OEM NO.:234-4071, 234-4401, 234-4127 Resolution:Oxygen Sensor Replaces OEM Part Number: 234-4071, 234-4401, 234-4127 "Please check the OE number clearly, confirm suited to your needs." Fit for: 2012 Ford E350 Super Duty V10 6.8L Upstream O2 Oxygen Sensor Set 2009-11 Ford E350 Super Duty V10 6.8L Upstream O2 Oxygen Sensor Set 2005-08 Ford Expedition V8 5.4L Upstream O2 Oxygen Sensor Set 2001-02 Ford Expedition V8 5.4L Upstream O2 Oxygen Sensor Set 2004-10 Ford Explorer V8 4.6L Upstream O2 Oxygen Sensor Set 1999-10 Ford Explorer V6 4.0L Upstream O2 Oxygen Sensor Set 1999-01 Ford Explorer V8 5.0L Upstream O2 Oxygen Sensor Set 2007-10 Ford Explorer Sport Trac V8 4.6L Upstream O2 Oxygen Sensor Set 2004-05 Ford Explorer Sport Trac V6 4.0L Downstream O2 Oxygen Sensor Set 2001-10 Ford Explorer Sport Trac V6 4.0L Upstream O2 Oxygen Sensor Set 2004 Ford F150 Heritage Truck V8 5.4L Upstream O2 Oxygen Sensor Set 2004 Ford F150 Heritage Truck SVT Lightning V8 5.4L Supercharged Upstream O2 Oxygen Sensor Set 2005-08 Ford F150 Truck V8 5.4L Upstream O2 Oxygen Sensor Set 2005-08 Ford F150 Truck V8 5.4L Downstream O2 Oxygen Sensor Set 2005-08 Ford F150 Truck V8 4.6L Upstream O2 Oxygen Sensor Set 2005-08 Ford F150 Truck V8 4.6L Downstream O2 Oxygen Sensor Set 2005-08 Ford F150 Truck V6 4.2L Upstream O2 Oxygen Sensor Set 2005-08 Ford F150 Truck V6 4.2L Downstream O2 Oxygen Sensor Set 2004 Ford F150 Truck with New Body Style V8 5.4L Upstream O2 Oxygen Sensor Set 2004 Ford F150 Truck with New Body Style V8 4.6L Upstream O2 Oxygen Sensor Set 2001-03 Ford F150 Truck V8 5.4L Upstream O2 Oxygen Sensor Set 2000-03 Ford F150 Truck Lightning V8 5.4L Supercharged Upstream O2 Oxygen Sensor Set 2004-07 Ford Freestar V6 4.2L Upstream O2 Oxygen Sensor Set 2004-07 Ford Freestar V6 3.9L Upstream O2 Oxygen Sensor Set 2001-11 Ford Ranger V6 4.0L Upstream O2 Oxygen Sensor Set 2001-11 Ford Ranger L4 2.3L Upstream O2 Oxygen Sensor Set 2001-08 Ford Ranger V6 3.0L Upstream O2 Oxygen Sensor Set 1999-03 Ford Windstar V6 3.8L Upstream O2 Oxygen Sensor Set 2006-08 Lincoln Mark LT V8 5.4L Upstream O2 Oxygen Sensor Set 2006-08 Lincoln Mark LT V8 5.4L Downstream O2 Oxygen Sensor Set 2005-08 Lincoln Navigator V8 5.4L Upstream O2 Oxygen Sensor Set 2001 Lincoln Navigator V8 5.4L Upstream O2 Oxygen Sensor Set 2001-09 Mazda B2300 Truck L4 2.3L Upstream O2 Oxygen Sensor Set 1999-07 Mazda B3000 Truck V6 3.0L Upstream O2 Oxygen Sensor Set 2004-09 Mazda B4000 Truck V6 4.0L Upstream O2 Oxygen Sensor Set 2004-07 Mercury Monterey V6 4.2L Upstream O2 Oxygen Sensor Set 2003-10 Mercury Mountaineer V6 4.0L Upstream O2 Oxygen Sensor Set 2002-10 Mercury Mountaineer V8 4.6L Upstream O2 Oxygen Sensor Set 1999-01 Mercury Mountaineer V8 5.0L Upstream O2 Oxygen Sensor Set 1999-01 Mercury Mountaineer V6 4.0L Upstream O2 Oxygen Sensor Set More adapter models please ask customer service Package included: 2Pcs Oxygen Sensor Note: 1. Please check OEM number before purchasing. 2. Please allow 1-3cm error due to manual measurement. Thanks for your understanding. 3. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. Must Know Before Buying: A: The only way to know if the O2 sensor is functioning normally is to check its responsiveness to changes in the air/fuel mixture, by Voltage Measurement or Waveform Simulation. Use a 10-megaohm digital voltmeter. Hook up the voltmeter's red probe to the sensor's signal wire and the black probe to engine ground. (Use back probe method, DO NOT pierce the wire.) For a good sensor, voltage should fluctuate constantly between 0.1 and 0.9 volts after starting the engine for 2 or 3 minutes. Please take a video clip of the voltmeter and contact us if our sensor: Goes above range between 0.1 and 0.9 volt Remains below 0.5 volts Stays fixed at a particular voltage You're free to choose replacement or refund if our sensor fails to work, in this case. Position confirmation: Upstream sensor is before the catalytic(cat.) converter. Downstream sensor is after the catalytic converter. Upstream oxygen sensor is also known as sensor 1, or pre-cat, or upper oxygen sensor. Downstream oxygen sensor is also known as sensor 2, or post-cat, or lower oxygen sensor. When should we replace the oxygen sensor : How to replace the oxygen sensor : Step 1 - Some sensors are equipped with a heat shield that must be removed before the sensor removal, this is performed by removing any mounting bolts. Step 2 - By