O2 Oxygen Sensor Upstream Downstream for Honda Civic (1997-2000) 1.6L

Direct-Fit Upstream Downstream O2 Sensor Kit for 1997-2000 Honda Civic (EJ6/EJ8)

What it Does: This matched upstream and downstream oxygen sensor kit monitors pre- and post-catalyst exhaust gas on the 1997-2000 Honda Civic (EJ6/EJ8 1.6L) to maintain closed-loop fuel trims and catalyst efficiency.

The Stock Honda Civic Oxygen Sensor Failure

Factory zirconia sensors on the EJ6/EJ8 chassis equipped with the D16Y7 / D16Y8 1.6L engine endure constant exhaust thermal cycling, carbon soot buildup, and silicone or coolant contamination. Over time, internal heater elements open-circuit and porous platinum electrodes lose response speed, causing sluggish voltage switching between rich and lean states. This forces the ECU into rich open-loop fueling and triggers P0135, P0141, P0131, or false P0420 fault codes.

Common Symptoms of a Failing OEM Oxygen Sensor

• Check Engine Light & DTCs: Triggers P0135, P0141, or P0420 from open heater circuits or sluggish voltage switching.
• Poor Fuel Economy: Rich open-loop compensation reduces MPG and fouls spark plugs.
• Drivability & Emissions Failure: Unstable air-fuel ratios cause rough idle, hesitation, and failed smog tests.

The Direct-Fit Zirconia Sensor Solution

This matched upstream and downstream kit uses fast-light-off heated zirconia sensing elements housed in corrosion-resistant stainless steel bodies with laser-welded protective shields. Factory-matched 4-wire harnesses, sealed OEM-style weatherpack connectors, and pre-applied anti-seize thread coatings ensure direct installation into the exhaust manifold and catalytic converter bungs without splicing. Built to meet OE spec 25024099, both sensors restore rapid closed-loop voltage switching and accurate catalyst monitoring on EJ6/EJ8 1.6L applications.

What's Included

• 1 Upstream Oxygen Sensor
• 1 Downstream Oxygen Sensor

Technical Specifications

Compatibility

• 1997-2000 Honda Civic 1.6L (Confirm engine before ordering)

Frequently Asked Questions & Fitment Warnings

Does this fit the EJ6/EJ8 Civic?

Yes. This is a direct fit for the 1997-2000 Honda Civic equipped with the D16Y7 / D16Y8 1.6L engine. Confirm engine code before ordering; excludes 5-wire lean-burn HX models.

Will this clear P0135, P0141, or P0420 codes?

Yes, for sensor faults. Installing both 25024099-spec units resolves heater and switching faults, though a P0420 from a degraded catalyst requires converter replacement.

Is wiring modification or hardware needed?

No. Direct-fit connectors plug directly into factory harnesses; torque to 33 lb-ft with a 22mm O2 socket.

The Honda Precision Standard

Built for EJ6/EJ8 1.6L Civics, this matched sensor set restores factory closed-loop fuel precision and crisp throttle response.