O2 Oxygen Sensor Upstream Downstream for Chevrolet Impala (2014-2020) 3.6L

Direct-Fit 4-Piece Oxygen Sensor Kit for 2014-2020 Chevrolet Impala (Epsilon II)

What it Does: The direct-fit oxygen sensor kit monitors pre- and post-catalytic exhaust gas oxygen content on the 2014-2020 Chevrolet Impala to maintain stoichiometric air-fuel ratios, lower emissions, and eliminate check engine diagnostics.

The Stock Chevrolet Impala Sensor Degradation

On the GM 3.6L LFX V6, factory planar sensors are exposed to extreme thermal cycling and combustion byproducts within the exhaust manifold and catalytic downpipes. Over time, internal zirconia ceramic elements glaze from carbon and fuel additives, while the internal heating circuits succumb to thermal fatigue. This degradation causes sluggish millivolt switching times, forcing the engine control module into skewed fuel trims, reduced fuel economy, rough idle, and persistent diagnostic trouble codes like P0131, P0137, P0420, or P0430.

The Engineering Solution

This four-sensor complete replacement package restores precise closed-loop ECM feedback across Bank 1 and Bank 2. Built with double-shielded, laser-welded stainless steel housings, these sensors resist thermal shock, moisture intrusion, and corrosion. Internal fast-acting ceramic heater substrates reach operational light-off temperature in seconds, reducing cold-start emissions. Each sensor features direct-fit weatherproof harness plugs and factory-correct pigtail lengths, eliminating splicing and matching OEM specifications for numbers such as 12590035 and 234-4566.

What's Included

• 2x Upstream Oxygen Sensors
• 2x Downstream Oxygen Sensors

Technical Specifications

Compatibility

• 2014-2020 Chevrolet Impala 3.6L V6 (LS, LT, Premier)

Frequently Asked Questions & Fitment Warnings

Does this fit the Epsilon II Impala?

Yes, this is a direct fit for the 2014-2020 Chevrolet Impala equipped with the 3.6L LFX engine. This kit is exclusively for 3.6L V6 models and does not fit 2.5L 4-cylinder or legacy Impala Limited models.

Do these sensors require wire splicing or adapter harnesses?

No, these sensors feature factory-style keyed connectors and specific wire lengths for direct, plug-and-play installation into the stock wiring harness.

The Chevrolet Caliber

Maintain the refinement and peak power delivery of your high-output V6. Replacing O2 sensors in full sets guarantees balanced bank-to-bank fuel metering, preserving downstream catalytic converters and ensuring smooth, efficient power across the entire RPM band.