O2 Oxygen Sensor Upstream Downstream for Hyundai Elantra (2004-2009) 2.0L

Direct-Fit Upstream & Downstream O2 Sensor Kit for 2004-2009 Hyundai Elantra (XD/HD)

What it Does: This matched upstream and downstream oxygen sensor kit monitors pre- and post-catalyst exhaust oxygen on 2004-2009 Hyundai Elantra (XD/HD) G4GC 2.0L Beta II models for closed-loop fuel control.

The Stock Hyundai Elantra Oxygen Sensor Failure

Factory oxygen sensors on the XD and HD chassis with the G4GC 2.0L Beta II engine endure severe thermal cycling above 1,400°F alongside carbon and oil-vapor contamination. Over time, internal zirconia elements poison, heater circuits open, and sensor louvers clog with soot. These failures slow switching response, locking the ECU into rich fueling and triggering P0130, P0135, and P0141 fault codes.

Common Symptoms of a Failing OEM Oxygen Sensor

• Check Engine Light & Heater DTCs: Triggers P0130, P0135, or P0141 when voltage response lags or heater resistance fails.
• Rough Idle & Hesitation: Corrupted air-fuel feedback skews injector pulse widths, causing stumble under acceleration.
• High Fuel Use & Emissions Failure: Rich open-loop operation spikes hydrocarbons, overheats the catalytic converter, and risks P0420 faults.

The Direct-Fit Upstream & Downstream Oxygen Sensor Solution

This matched sensor pair restores precise air-fuel metering using laser-welded stainless steel housings and double-layered protective shields that resist exhaust condensate shock. High-purity ceramic zirconia sensing elements deliver rapid heater warm-up and crisp millivolt switching for stoichiometric 14.7:1 combustion under load. Each direct-fit assembly features OEM weatherproof connectors and pre-cut threads, replacing 234-5430, SG1495, and SG1485 without cutting or splicing.

What's Included

• 1 Upstream Oxygen Sensor
• 1 Downstream Oxygen Sensor

Technical Specifications

Compatibility

• 2004-2009 Hyundai Elantra 2.0L (Confirm engine before ordering)

Frequently Asked Questions & Fitment Warnings

Does this fit the XD/HD Elantra?

Yes. This is a direct fit for the 2004-2009 Hyundai Elantra equipped with the G4GC 2.0L Beta II engine. Does not fit non-2.0L engines; confirm engine displacement before ordering.

Will this clear P0135, P0141, or fuel trim codes?

Yes. Replacing failed upstream and downstream sensors restores heater circuit integrity and rapid O2 switching, clearing P0130, P0135, and P0141 once the ECU completes drive-cycle verification.

Are factory connectors included for bolt-on installation?

Yes. Both sensors come with direct-fit OEM plugs—apply anti-seize only to threads and torque to 30–37 lb-ft.

The Hyundai Precision Standard

Engineered to factory tolerances, this matched sensor kit preserves closed-loop ECU accuracy and emissions compliance across daily driving. Maintain factory fuel economy and CEL-free operation on your XD/HD Elantra.