{"product_id":"ntk-25645-oxygen-sensor-downstream-left-or-downstream-right","title":"NTK 25645 Oxygen Sensor - Downstream Left or Downstream Right","description":"\u003ch2\u003eDirect-fit oxygen sensor\u003c\/h2\u003e\u003cp\u003eNTK Oxygen Sensor 25645 is a direct-fit, heated oxygen sensor built for specific applications. It is engineered for threaded mounting and uses a 4-wire design with a 63.7500 wiring harness length for a precise replacement on compatible vehicles.\u003c\/p\u003e\u003ch2\u003eKey features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eHeated oxygen sensor for faster operating response.\u003c\/li\u003e\n\u003cli\u003eSpecific-fit design for direct replacement applications.\u003c\/li\u003e\n\u003cli\u003eThreaded mounting with an 18.000 thread diameter.\u003c\/li\u003e\n\u003cli\u003e4-wire configuration for the correct signal setup.\u003c\/li\u003e\n\u003cli\u003e63.7500 wiring harness length for application-specific routing.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed description\u003c\/h2\u003e\u003cp\u003eNTK 25645 is part of the Direct Fit Oxygen Sensor line, which focuses on application-specific replacement parts rather than universal coverage. NTK draws on its OE sensor manufacturing background to deliver fit, form, and function that align with original equipment requirements. This oxygen sensor is listed for 2001-2003 Audi A8 Quattro applications in downstream left and downstream right positions, making it a targeted replacement for those emission control locations. The part number 25645 is also useful when cross-checking catalog listings and service references.\u003c\/p\u003e\u003cp\u003eThis part cross-references Bosch 16073 and DENSO Auto Parts 234-4812 for the same application.\u003c\/p\u003e\u003ch2\u003eWhat it is used for\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eReplacing a worn or slow-responding oxygen sensor.\u003c\/li\u003e\n\u003cli\u003eRestoring proper exhaust gas feedback to the engine control system.\u003c\/li\u003e\n\u003cli\u003eAddressing sensor fault codes related to oxygen sensor performance.\u003c\/li\u003e\n\u003cli\u003eCorrecting drivability issues tied to inaccurate air-fuel monitoring.\u003c\/li\u003e\n\u003cli\u003eReplacing a damaged threaded sensor with the correct fitment.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation notes and tips\u003c\/h2\u003e\u003cp\u003eVerify the downstream left or downstream right position before ordering. Confirm the 4-wire connector style, threaded mounting, and harness length against the original sensor on the vehicle. For 2001-2003 Audi A8 Quattro applications, match the OE-equivalent placement and sensor configuration to avoid fitment errors.\u003c\/p\u003e\u003ch2\u003eQuality assurance\u003c\/h2\u003e\u003cp\u003eNTK states that these oxygen sensors are extensively tested during manufacturing and built to meet or exceed OE specifications. The brand is part of the NGK family of products and is recognized as a major original equipment oxygen sensor supplier.\u003c\/p\u003e","brand":"NTK","offers":[{"title":"Default Title","offer_id":53731440394421,"sku":"BFPZ-25645","price":125.69,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/NO_25645_Fro.jpg?v=1794296573","url":"https:\/\/www.partcatalog.com\/products\/ntk-25645-oxygen-sensor-downstream-left-or-downstream-right","provider":"PartCatalog","version":"1.0","type":"link"}