O2 Oxygen Sensor Upstream Downstream for Buick Encore (2013-2021) 1.4L Turbo

Direct-Fit Upstream & Downstream O2 Sensor Kit for 2013-2021 Buick Encore (Gamma II)

What it Does: This matched upstream and downstream oxygen sensor set restores closed-loop fueling and catalyst monitoring on the 2013-2021 Buick Encore Gamma II LUV 1.4L Turbo.

The Stock Buick Encore O2 Sensor Failure

Factory oxygen sensors on the Gamma II platform endure severe thermal cycling near the LUV 1.4L Ecotec Turbo exhaust manifold and catalytic converter outlet. Over time, PCV oil mist, silicon contamination, and carbon soot foul the zirconia tip, slowing voltage switching response. Meanwhile, internal ceramic heater elements suffer resistance drift and burnout from vibration and heat soak, triggering P0135, P0141, or P0171 codes.

Common Symptoms of a Failing OEM O2 Sensor

• Heater & Circuit DTCs: P0135, P0141, or P0131 trigger when heater circuits open or response lags.
• Fuel Trim Drift: Sluggish upstream feedback causes erratic fueling and turbo hesitation under load.
• Poor Economy & Emissions: Lost closed-loop control lowers MPG and fails OBD-II inspections.

The Direct-Fit Heated Zirconia O2 Sensor Solution

This matched two-sensor kit replaces both upstream and downstream units with factory-calibrated heated zirconia elements for rapid light-off and crisp millivolt switching. Laser-welded stainless housings, high-temp sleeves, and OEM weatherproof plugs connect directly to the factory harness. Pre-applied anti-seize simplifies bung installation while matching OEM specs for 234-4528, 234-4529, 55572216, 55574136, and 55572993.

What's Included

• 1 Upstream Oxygen Sensor
• 1 Downstream Oxygen Sensor

Technical Specifications

Compatibility

• 2013-2021 Buick Encore 1.4L Turbocharged (2-Sensor Layout; Confirm Engine Before Ordering)

Frequently Asked Questions & Fitment Warnings

Does this fit the Gamma II Encore?

Yes. Fits the 2013-2021 Buick Encore LUV 1.4L Turbo two-sensor layout. Confirm your 1.4L engine before ordering; other GM models are excluded.

Will this clear P0135 or P0141 codes?

Yes. Restores heater continuity and feedback for P0135 and P0141; persistent P0420 codes indicate catalyst failure.

Are plugs and thread prep included?

Yes. Includes factory connectors and pre-coated threads; clear stored ECM codes after installation.

The Buick Precision Standard

Built for strict emissions compliance and accurate ECM communication, this matched pair keeps your Encore CEL-free with reliable fuel trim control.