O2 Oxygen Sensor Upstream Downstream for Hyundai Elantra (2011-2016) 1.8L

Direct-Fit Upstream & Downstream O2 Sensor Kit for 2011-2016 Hyundai Elantra (MD)

What it Does: This matched upstream and downstream O2 sensor kit restores closed-loop fuel control and catalyst monitoring on 2011-2016 MD Hyundai Elantra 1.8L models.

The Stock Hyundai Elantra O2 Sensor Failure

On the MD Elantra equipped with the G4NB 1.8L Nu engine, factory upstream wideband and downstream switching sensors endure extreme thermal cycling and exhaust soot contamination. Over time, oil ash and fuel additives glaze the zirconia element, slowing voltage response and skewing fuel trims. Internal heater circuit degradation also causes resistance spikes, triggering P0131, P0134, and P0420 codes while forcing inefficient open-loop fueling.

Common Symptoms of a Failing OEM O2 Sensor

• Check Engine Light / DTCs: Triggers P0131, P0134, or P0420 from slow lambda switching or heater faults.
• Skewed Fuel Trims: Glazed upstream elements report false lean readings, causing rich compensation and poor MPG.
• Rough Idle & Failed Emissions: Delayed ECU feedback causes idle stumble and elevated tailpipe hydrocarbons.

The Direct-Fit Planar Zirconia O2 Sensor Solution

This matched sensor kit replaces worn OEM units 234-5082 and 234-4552 with direct-fit planar zirconia elements engineered for rapid light-off. Laser-welded 310S stainless housings resist thermal shock and corrosion, while porous PTFE shields block moisture and particulate fouling. Factory-length heat-resistant harnesses and OEM locking connectors guarantee direct plug-and-play installation into the G4NB 1.8L Nu exhaust manifold and mid-pipe bungs without wire splicing.

What's Included

• 1x Upstream Oxygen Sensor (234-5082)
• 1x Downstream Oxygen Sensor (234-4552)

Technical Specifications

Compatibility

• 2011-2014 Hyundai Elantra 1.8L (California Emissions, 2-sensor setup)
• 2015-2016 Hyundai Elantra 1.8L (2-sensor setup)
• Excludes 2.0L engines, Elantra Coupe, Elantra GT, and other Hyundai/Kia models; confirm engine and emissions before ordering.

Frequently Asked Questions & Fitment Warnings

Does this fit the MD Elantra?

Yes. Fits 2011-2016 Hyundai Elantra G4NB 1.8L Nu models. Excludes 2.0L, Elantra Coupe, Elantra GT, and non-California 2011-2014 emissions models.

Will this clear P0134 and P0420 codes?

Yes, when sensor-induced. Replacing 234-5082 and 234-4552 restores ECU lambda feedback; inspect the catalyst if P0420 persists.

Is wire splicing required for installation?

No. Both sensors feature factory locking plugs and pre-coated threads for direct exhaust bung installation.

The Hyundai Precision Standard

Matched lambda feedback on the MD Elantra keeps the G4NB 1.8L Nu at peak stoichiometric efficiency and emissions compliance. Direct-fit connectors eliminate CEL guesswork for reliable daily operation.