This 4-wire heated planar oxygen (lambda) sensor is a genuine Hyundai and Kia original equipment component, identified by OE part number 39210-2B040. It functions as the upstream (pre-catalyst / front) regulating sensor, installed before the catalytic converter to provide the engine control unit with precise air-fuel ratio feedback. Manufactured to Hyundai and Kia OE specifications, it delivers reliable emissions control and fuel trim accuracy for a wide range of petrol-powered Hyundai and Kia vehicles.

• This is a 4-wire heated planar-type oxygen sensor built to Hyundai and Kia original equipment standards. The four wires serve two independent circuits — two for the internal heater and two for the sensor signal and ground.
• The built-in heating element rapidly brings the ceramic sensing tip to operating temperature after a cold start, allowing the ECU to enter closed-loop fuel control sooner and reducing cold-start emissions.
• As an upstream (pre-catalyst / front) regulating sensor, it is installed before the catalytic converter and acts as the primary regulating probe that directly influences the ECU's fuel trim adjustments.
• The planar probe design offers faster light-off and more precise measurement than older thimble-type sensors.
• Features a 4-pin connector and a factory pre-greased thread for quick, straightforward installation.
• Cable length variations: Documented lengths for this OE number include 450 mm (FACET, HERTH+BUSS) and 550 mm (DENSO), depending on the aftermarket manufacturer. Always measure your original sensor before ordering.
• All sensors are manufactured to meet or exceed original equipment quality standards.
• Also known as: O2 Sensor, Lambda Sensor, Front Oxygen Sensor, Pre-Catalyst Sensor, Exhaust Gas Sensor.

The following OE numbers are directly interchangeable or closely related to 39210-2B040. These references are frequently grouped together across multiple aftermarket catalogues.

• DENSO DOX-2062 is a widely documented direct-fit equivalent with specifications: 4-pin connector, 550 mm cable length, M18×1.5 thread, 118 g weight, heated planar sensor, thread pre-greased.
• FACET 10.8256 / EPS 1.998.256 lists 39210-2B040, 39210-03000, and 39210-02660 as equivalent OE references, with 450 mm cable length, heated planar probe, and pre-greased thread.
• FEBI BILSTEIN 175869 lists 39210-2B040 alongside 3921002660, 392102E771, 392103F000, and other Hyundai/Kia OE numbers.
• VEMO V53-76-0007 is listed as a diagnostic probe with pre-greased thread, compatible with Hyundai i10 PA, i20 Mk1, Atos MX, and Kia Picanto Mk1, Soul AM.
• ERA 570320A lists 39210-2B040 for Hyundai i20, Santa Fe I, Sonata III/IV, Trajet; Kia Cee'd, Cerato II, Joice, Pro Cee'd, Soul I applications.
• HERTH+BUSS JAKOPARTS J1460341 specifies 450 mm cable length and notes a 22 mm slotted lambda sensor socket wrench and 40–55 Nm torque.
• BLUE PRINT ADBP700030 specifies 560 mm cable length and M18×1.5 external thread.
• Always physically compare your old sensor's connector shape (4-pin), cable length, and thread size (M18 × 1.5) before purchasing.

This Lambda Sensor is an original equipment component used across a range of Hyundai and Kia vehicles. Based on extensive cross-reference data, the sensor is installed in the upstream (pre-catalyst / front) position.

• This is an upstream (pre-catalyst / before catalytic converter) oxygen sensor. It is installed before the catalytic converter and serves as the primary regulating probe for air-fuel mixture control.
• Primary applications include Hyundai i10 (2010–2013), Hyundai i20 (2008–2014), Hyundai Santa Fe (2000–2006), Hyundai Sonata (1998–2005), Hyundai Trajet (2000–2008); Kia Cee'd (2006–2012), Kia Cerato (2008–2013), Kia Soul (2009–2013), and Kia Picanto (2004–2011) with 1.0L, 1.1L, 1.2L, 1.4L, 1.6L, and selected 2.0L/2.4L/2.7L V6 petrol engines.
• How to verify: Locate your vehicle's catalytic converter. The upstream sensor is typically installed in the exhaust manifold or in the pipe immediately before the catalytic converter. If your faulty sensor is located before the converter, this part is suitable.
• Not compatible with diesel engines — diesel applications use different sensors with different calibration parameters.
• The vehicle fitment information above is a guide only. Always confirm compatibility using your vehicle's VIN or by physically inspecting your old sensor's position, connector shape, and cable length before ordering.