{"product_id":"ntk-25640-oxygen-sensor-upstream","title":"NTK 25640 Oxygen Sensor - Upstream","description":"\u003ch2\u003eDirect-Fit Oxygen Sensor\u003c\/h2\u003e\u003cp\u003eThis NTK oxygen sensor is a specific-fit, heated replacement built for emission control applications. It is engineered for direct installation and supports accurate exhaust monitoring on compatible vehicles.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eHeated oxygen sensor with a 4-wire design for stable signal performance.\u003c\/li\u003e\n\u003cli\u003eThreaded mounting with an 18 mm thread diameter.\u003c\/li\u003e\n\u003cli\u003e34.75-inch wiring harness length for application-specific routing.\u003c\/li\u003e\n\u003cli\u003eNTK Direct Fit Oxygen Sensor line focuses on OE-style fit, form, and function.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eApplication Details\u003c\/h2\u003e\u003cp\u003eFits 1995 Volkswagen Passat, upstream. This part number 25640 is listed for B1S1 applications from chassis 3A-S-202 677 and uses an OE-equivalent direct-fit design. For buyers searching for a 1995 Volkswagen Passat upstream oxygen sensor, part number 25640 matches the specified application.\u003c\/p\u003e\u003ch2\u003eCommon Issues It May Address\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eFaulty oxygen sensor readings that can affect fuel control.\u003c\/li\u003e\n\u003cli\u003eCheck engine light concerns related to upstream exhaust monitoring.\u003c\/li\u003e\n\u003cli\u003eRough idle or drivability issues caused by inaccurate air-fuel feedback.\u003c\/li\u003e\n\u003cli\u003eEmission test failures tied to a worn sensor.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\u003cp\u003eVerify the upstream location, chassis break, and OE-equivalent design before installation. Confirm the threaded mounting style, 18 mm thread diameter, and harness length against the original sensor. Use the vehicle service information for proper routing and connector matching on the Volkswagen Passat application.\u003c\/p\u003e\u003ch2\u003eQuality Assurance\u003c\/h2\u003e\u003cp\u003eNTK states that these oxygen sensors are extensively tested during manufacturing to meet or exceed OE specifications. The brand is part of the NGK family and is recognized for OE oxygen sensor manufacturing and application coverage. Part number 25640 is supported by NTK's direct-fit product line for import and domestic applications.\u003c\/p\u003e","brand":"NTK","offers":[{"title":"Default Title","offer_id":53731440033973,"sku":"BFPZ-25640","price":82.44,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/NO_25640_Fro.jpg?v=1794296543","url":"https:\/\/www.partcatalog.com\/products\/ntk-25640-oxygen-sensor-upstream","provider":"PartCatalog","version":"1.0","type":"link"}