O2 Oxygen Sensor Upstream Downstream for Honda Civic (2016-2020) 1.5L

Direct-Fit Upstream & Downstream O2 Sensor Kit for 2016-2020 Honda Civic (FC1/FC3/FK7)

What it Does: Monitors pre- and post-catalyst exhaust oxygen on the 2016-2020 Honda Civic FC1/FC3/FK7 (L15B7 1.5L Turbo) to regulate air-fuel stoichiometry and verify catalyst efficiency.

The Stock Honda Civic Sensor Failure

Factory oxygen sensors on the FC1/FC3/FK7 Civic with the direct-injected L15B7 1.5L Turbo endure extreme exhaust heat and fuel dilution blow-by. Thermal cycling fractures the ceramic zirconia element while carbon soot poisons the platinum electrodes and slows voltage response. Internal heater circuits also suffer high-resistance failures, delaying closed-loop fueling and triggering P0135, P0141, or P2A00 codes.

Common Symptoms of a Failing OEM Oxygen Sensor

• Check Engine Light / DTCs: Triggers P0134, P0135, P0141, or P0171 from open heater circuits or skewed lambda feedback.
• Sluggish Closed-Loop Response: Carbon-fouled tips cause erratic fuel trims and hesitation under boost.
• Failed Emissions & MPG Drop: Rich fueling raises consumption and triggers P0420 faults.

The Direct-Fit Matched O2 Sensor Solution

Replacing both sensors as a matched set restores accurate lambda feedback on your L15B7 1.5L Turbo. The upstream unit (234-5724) uses a fast-response planar element for precise air-fuel tracking under boost, while the downstream sensor (234-8027) verifies catalyst oxygen storage. Corrosion-resistant stainless housings, laser-welded shields, and OEM-style weatherproof connectors thread directly into factory bungs without splicing.

What's Included

• 1x Upstream Oxygen Sensor (234-5724)
• 1x Downstream Oxygen Sensor (234-8027)

Technical Specifications

Compatibility

• 2016-2020 Honda Civic 1.5L (L15B7) — Confirm engine before ordering

Frequently Asked Questions & Fitment Warnings

Does this fit the FC1/FC3/FK7 Civic?

Yes. Direct fit for 2016-2020 Honda Civic L15B7 1.5L Turbo models. Excludes 2.0L (K20C2) and Type R (K20C1) engines; confirm engine before ordering.

Will this clear P0135/P0141 codes, and are both sensors included?

Yes. Includes both upstream (234-5724) and downstream (234-8027, replacing 36532-5AA-A01 / 36532-5AA-A51) sensors to resolve heater and response faults.

Are OEM connectors pre-wired for bolt-on installation?

Yes. Both sensors include OEM-matched plugs for plug-and-play installation into factory exhaust bungs.

The Honda Precision Standard

Engineered for crisp throttle response and accurate closed-loop fueling under boost, this matched sensor kit keeps your L15B7 running clean and CEL-free.