O2 Oxygen Sensor Upstream Downstream for Hummer H2 (2003-2006) 6.0L

Direct-Fit Replacement Oxygen Sensor Set for 2003-2006 Hummer H2 (GMT820)

What it Does: The complete 4-piece oxygen sensor set restores closed-loop fuel trim accuracy and catalytic monitoring on the 2003-2006 Hummer H2 to eliminate check engine lights and recover lost fuel economy.

The Stock Hummer H2 Sensor Degradation

Factory zirconia O2 sensors operating in the high-heat exhaust stream of the heavy GMT820 chassis suffer from thermal fatigue, silica contamination, and soot accumulation over time. As internal ceramic sensing elements age, their response rate slows significantly. In the Vortec 6000 LQ4, sluggish upstream feedback forces the powertrain control module (PCM) into rich or lean boundary hunting, spiking fuel consumption and triggering diagnostic trouble codes such as P0130 through P0161, or false catalytic inefficiency codes like P0420 and P0430.

The Engineering Solution

This four-sensor replacement kit features planar ceramic sensing elements housed in double-protection stainless steel casings to resist thermal shock and exhaust particulate fouling. Each sensor utilizes factory-calibrated internal heater circuits for rapid light-off and stable closed-loop transition. Fitted with OEM-specification dual-shielded pigtails, weather-pack connectors, and pre-applied high-temperature thread anti-seize, these sensors ensure plug-and-play installation without wire splicing or pin relocation.

What's Included

• 2 Upstream Oxygen Sensors
• 2 Downstream Oxygen Sensors

Technical Specifications

Compatibility

• 2003 Hummer H2 Base Sport Utility 4-Door 6.0L V8
• 2004 Hummer H2 Base Sport Utility 4-Door 6.0L V8
• 2005 Hummer H2 Base Sport Utility / SUT Crew Cab Pickup 4-Door 6.0L V8
• 2006 Hummer H2 Base Sport Utility / SUT Crew Cab Pickup 4-Door 6.0L V8

Frequently Asked Questions & Fitment Warnings

Does this fit the GMT820 H2?

Yes, this is a direct fit for the 2003-2006 Hummer H2 equipped with the 6.0L LQ4 V8 engine.

Do I need special tools to complete the installation?

A dedicated 7/8-inch (22mm) slotted oxygen sensor socket is recommended to avoid damaging the sensor harness during removal and torquing.

The Hummer Durability Standard

Built to handle the immense thermal and mechanical demands of heavy-duty towing and rugged off-road operation, these sensors ensure precise air-fuel ratios to keep your H2 running reliably under heavy loads.