O2 Oxygen Sensor Upstream Downstream for GMC Canyon (2007-2012) 3.7L

Direct-Fit Upstream & Downstream Oxygen Sensor Kit for 2007-2012 GMC Canyon (GMT355)

What it Does: This matched O2 sensor kit monitors upstream and downstream exhaust oxygen on the GMT355 2007-2012 GMC Canyon (LLR 3.7L) to regulate closed-loop fuel trims and catalyst efficiency.

The Stock GMC Canyon Oxygen Sensor Failure

Factory heated O2 sensors on the GMT355 platform equipped with the LLR 3.7L engine routinely suffer thermal fatigue, internal heater circuit burnout, and zirconia element contamination from oil ash or carbon buildup. As the upstream sensing element slows, fuel trims drift excessively rich or lean, overloading the catalytic converter. Simultaneously, degraded downstream sensors fail to stabilize voltage readings, triggering persistent P0135, P0141, P0171, and P0420 fault codes.

Common Symptoms of a Failing OEM Oxygen Sensor

• Check Engine Light & DTCs: Triggers heater circuit codes like P0135 or P0141, slow response P0133, or catalyst efficiency P0420.
• Sluggish Throttle & Rough Running: Erratic voltage forces open-loop fueling, causing exhaust soot and hesitation under load.
• Failed Emissions & Low MPG: Uncalibrated air-fuel ratios drop fuel economy and block OBD-II readiness monitors.

The Direct-Fit Upstream & Downstream O2 Sensor Solution

This matched direct-fit O2 sensor pair restores factory closed-loop lambda feedback across both Bank 1 Sensor 1 and Bank 1 Sensor 2 positions on your GMT355 Canyon. Built with fast-acting ceramic elements, laser-welded stainless steel housings, and factory-spec weather-sealed connectors, each unit resists thermal shock and moisture ingress. Replacing upstream and downstream sensors together eliminates response lag and bolts directly into factory bungs without splicing.

What's Included

• 1x Upstream Oxygen Sensor
• 1x Downstream Oxygen Sensor

Technical Specifications

Compatibility

• 2007-2012 GMC Canyon (3.7L LLR Engine Only)

Frequently Asked Questions & Fitment Warnings

Does this fit the GMT355 Canyon?

Yes. Fits 2007-2012 GMC Canyon with the LLR 3.7L engine. Excludes 2.9L Canyon and Chevrolet Colorado models; confirm engine before ordering.

Will this clear P0135, P0141, and P0420 codes?

Yes, if sensors are faulty. Restores heater resistance and switching speed to clear P0135/P0141; a persistent P0420 indicates a worn catalyst.

Are connectors direct-fit for installation?

Yes, no splicing is required. Both sensors use OEM-style connectors and fit factory exhaust bungs using a 22mm O2 sensor socket.

The GMC Heavy-Duty Standard

Built for high exhaust heat and vibration on the GMT355 Canyon, keeping your LLR 3.7L running clean and CEL-free.