O2 Oxygen Sensor Rear Downstream for Chevy GMC Pickup Truck (2002-2007)

Stop burning more fuel than necessary in your big-block or heavy-duty hauler and finally clear that Check Engine Light with a direct-fit sensor replacement.

Replacement Oxygen Sensor for Chevy Silverado, GMC Sierra & Hummer H2 (6.0L / 8.1L Vortec)

If you are driving a heavy-duty GM truck from the early 2000s, you know that the Vortec 6.0L and the massive 8.1L Big Block are legendary for their towing capacity, but they aren't exactly known for sipping fuel. When an oxygen sensor fails on these rigs, your mileage can drop from "tolerable" to "painful" very quickly. A slow or dead O2 sensor sends incorrect data to the ECU, forcing the engine to run rich as a safety precaution. This doesn't just hurt your wallet at the pump; it can foul your spark plugs and eventually damage your catalytic converters.

This replacement Oxygen Sensor is designed specifically for the heavy-duty applications of the GMT800 platform and related SUVs like the Hummer H2. Unlike universal "one-size-fits-all" sensors that require you to strip wires and crimp connectors, this unit features the correct factory-style Gray connector and a 580mm wire harness. It is a true plug-and-play solution. Whether you are dealing with a rough idle, a failed emissions test, or just a glowing dashboard light, this sensor provides the accurate air/fuel ratio data your truck needs to run efficiently.

Built to strict quality control standards, this 4-wire sensor handles the high-heat environment of a working truck. It is designed to replace the specific dealer part numbers listed below, ensuring that the resistance and signal range match what your GM engine computer expects. Get your tow rig back to peak performance without the hassle of wire splicing.

Why You Need This Upgrade

• Restore Fuel Economy: Replaces aging sensors that cause the engine to run "rich," helping you reclaim lost MPGs on your 6.0L or 8.1L.
• Direct Plug-and-Play: Features the correct Gray plug and 4-wire configuration, so no cutting, splicing, or soldering is required.
• Perfect Fitment: The 580mm (approx. 23 inch) wire length is sized to reach the factory harness clip without tension or excess slack.
• Emissions Compliance: Accurate sensor data is critical for passing smog tests and keeping your catalytic converter healthy.
• Engine Health: Helps resolve rough idling and hesitation caused by improper fuel mixture adjustments.

Installation Notes

Installation is straightforward but requires working around a hot exhaust system—always let the vehicle cool completely before starting. A specialized slotted O2 sensor socket is highly recommended to remove the old sensor without rounding off the hex head. This sensor features a Gray connector; please visually verify your existing sensor plug color matches before ordering, as GM sometimes used different color keys for different positions.

Replaces These OEM Applications & Part Numbers

• GMC Yukon 6.0L V8 / 8.1L V8 2002-2006
• GMC Sierra 3500 6.0L V8 2002-2007
• GMC Sierra 2500 HD 6.0L V8 / 8.1L V8 2002-2007
• GMC Sierra 1500 6.0L V8 2002-2007
• Chevrolet Silverado 3500 6.0L V8 2002-2007
• Chevrolet Silverado 2500 6.0L V8 2002-2007
• Chevrolet Silverado 1500 HD 6.0L V8 2001-2007
• Chevrolet Suburban 2500 6.0L V8 2002
• Hummer H2 6.0L V8 2003
• Cadillac Escalade ESV/EXT 6.0L V8 2003-2004

234-4286, 25333812, 25333817, SG970

Don't let a $50 part cost you hundreds in fuel—replace your faulty Oxygen Sensor today and keep your Vortec running right.