{"product_id":"delphi-es20421-oxygen-sensor","title":"Delphi ES20421 Oxygen Sensor - Rear","description":"\u003ch2\u003eDelphi ES20421 Heated Oxygen Sensor Overview\u003c\/h2\u003e\u003cp\u003eThe Delphi ES20421 is a heated oxygen sensor designed for precise emission control in select BMW models. Engineered with a 4-wire configuration and a flat connector shape, this sensor ensures accurate readings and reliable performance in the rear left position of your vehicle's exhaust system.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHeated oxygen sensor with 4 wires for efficient operation\u003c\/li\u003e\n\u003cli\u003eFlat connector shape for secure and easy installation\u003c\/li\u003e\n\u003cli\u003eThread size of 18 x 1.5 mm compatible with specified BMW models\u003c\/li\u003e\n\u003cli\u003eOverall length of 765.0 mm to fit rear exhaust positions\u003c\/li\u003e\n\u003cli\u003eIncludes oxygen sensor and instruction sheet for installation guidance\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eTechnical Details and Compatibility\u003c\/h2\u003e\u003cp\u003eThe Delphi ES20421 oxygen sensor is specifically designed for emission control systems requiring a heated sensor type. Its 4-wire design supports both sensor heating and signal transmission, improving sensor response time and accuracy. The flat connector shape facilitates a reliable electrical connection, reducing the risk of disconnection or corrosion. With a thread size of 18 x 1.5 mm and an overall length of 765.0 mm, this sensor fits the rear left position on various BMW models including the 135i, 335i, 528i, 535i, 640i, 740i, ActiveHybrid series, and X series SUVs. For exact position compatibility, refer to your vehicle’s specifications.\u003c\/p\u003e\u003ch2\u003eApplications and Problem Resolution\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eHelps maintain optimal air-fuel mixture for efficient combustion\u003c\/li\u003e\n\u003cli\u003eReduces harmful emissions by providing accurate oxygen level data\u003c\/li\u003e\n\u003cli\u003eAddresses issues such as poor fuel economy and rough idling\u003c\/li\u003e\n\u003cli\u003ePrevents check engine light triggers related to oxygen sensor faults\u003c\/li\u003e\n\u003cli\u003eSupports proper operation of catalytic converters and emission systems\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eWhen installing the Delphi ES20421 oxygen sensor, ensure the vehicle is cool to avoid burns. Use the included instruction sheet for guidance on connector alignment and torque specifications. Verify the sensor’s position as rear left or rear according to your BMW model’s requirements. Avoid over-tightening the sensor to prevent thread damage. It is recommended to inspect wiring and connectors for corrosion or damage before installation.\u003c\/p\u003e\u003ch2\u003eQuality Assurance and Warranty\u003c\/h2\u003e\u003cp\u003eDelphi oxygen sensors are manufactured to meet OEM standards for durability and performance. The ES20421 part number undergoes rigorous testing to ensure reliable operation under various driving conditions. While specific warranty details may vary, Delphi typically offers coverage against manufacturing defects. Consult product documentation or your supplier for exact warranty terms.\u003c\/p\u003e","brand":"Delphi","offers":[{"title":"Default Title","offer_id":43388535701685,"sku":"BBMX-ES20421","price":186.11,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/DE_ES20421_Fro.jpg?v=1774712097","url":"https:\/\/www.partcatalog.com\/products\/delphi-es20421-oxygen-sensor","provider":"PartCatalog","version":"1.0","type":"link"}