{"product_id":"sangyue-o2-oxygen-sensor-kit-2-pack-upstream-downstream-for-2004-2005-4-2l-direct-fit-oem-wiring","title":"Sangyue O2 Oxygen Sensor Kit 2-Pack Upstream \u0026 Downstream for 2004–2005 4.2L — Direct-Fit OEM Wiring","description":"\u003cstrong\u003eThe Sangyue 2X Oxygen O2 Sensor kit is a pair of upstream and downstream O2 sensors engineered to replace the factory sensors in select 2004–2005 GM and related vehicles.\u003c\/strong\u003e\n\n\u003cp\u003eThis two-piece sensor set includes one upstream (pre-catalytic converter) and one downstream (post-catalytic converter) oxygen sensor designed to restore accurate air–fuel feedback for compatible engines. Each sensor is built to match OEM fitment dimensions and wiring terminals for the listed 2004–2005 models, helping simplify installation while maintaining the vehicle’s emissions monitoring capability.\u003c\/p\u003e\n\n\u003ch3\u003eWhich vehicles and engines does this Sangyue O2 sensor set fit?\u003c\/h3\u003e\n\u003cp\u003eThis kit is specified for a range of GM-family vehicles from 2004 to 2005 and some rebadged models that share the same 4.2L or specified engines. Always verify fitment using the vehicle selector (make, model, year, engine) before ordering to avoid compatibility issues.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFits 2004–2005 Chevrolet Trailblazer and Trailblazer EXT 4.2L.\u003c\/li\u003e\n  \u003cli\u003eCompatible with 2004–2005 Buick Rainier 4.2L and GMC Envoy\/Envoy XL\/Envoy XUV 4.2L.\u003c\/li\u003e\n  \u003cli\u003eAlso listed for 2004–2005 Isuzu Ascender 4.2L, 2004 Oldsmobile Bravada 4.2L, 2005 Saab 9-7X 4.2L.\u003c\/li\u003e\n  \u003cli\u003eSome Colorado and Canyon model years\/engines included—double-check engine displacement and wiring before purchase.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do these upstream and downstream sensors differ and why both matter?\u003c\/h3\u003e\n\u003cp\u003eThe upstream sensor measures exhaust oxygen before the catalytic converter to help the engine control unit manage fuel delivery. The downstream sensor monitors the converter’s efficiency after the catalyst, used for emissions diagnostics. Replacing both ensures accurate feedback loops and reduces the chance of lingering diagnostic trouble codes.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eUpstream: provides real-time air–fuel ratio feedback to the ECU.\u003c\/li\u003e\n  \u003cli\u003eDownstream: confirms catalytic converter performance for emissions systems.\u003c\/li\u003e\n  \u003cli\u003eSold together to match response characteristics and wiring for seamless operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat can I expect during installation and performance after replacement?\u003c\/h3\u003e\n\u003cp\u003eThese sensors are designed for a direct replacement where mounting threads and connector types match OEM specifications. Installation typically requires common hand tools and should follow standard safety procedures for working on the exhaust system. After replacement, expect stable sensor readings and elimination of oxygen-sensor-related error codes if the rest of the exhaust and fuel system are in good condition.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect-fit design intended to plug into factory wiring harnesses.\u003c\/li\u003e\n  \u003cli\u003eStandard threaded mounting—anti-seize may be pre-applied or recommended to use.\u003c\/li\u003e\n  \u003cli\u003eCommon installation time: 30–90 minutes depending on access and rust\/corrosion.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat warranty and quality assurances come with this Sangyue sensor set?\u003c\/h3\u003e\n\u003cp\u003eThe product is offered with a one-year unlimited-mileage quality guarantee to protect against manufacturing defects. That coverage helps provide confidence during the first year of use; retain purchase documentation for warranty claims.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOne-year unlimited mileage quality guarantee included.\u003c\/li\u003e\n  \u003cli\u003eSold as a matched pair (2pcs) — upstream and downstream sensors.\u003c\/li\u003e\n  \u003cli\u003eCheck vehicle selector (make, model, year, engine) before purchase to confirm fitment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: This Sangyue 2X O2 sensor set is suitable for DIY mechanics and professional technicians restoring oxygen-sensor functionality on 2004–2005 GM-platform vehicles and related rebadged models with the specified engines. It’s ideal for anyone replacing aging or failed sensors, clearing sensor-related trouble codes, or ensuring the emissions system has correct feed-back after catalytic converter service. Always confirm engine displacement and connector type with your vehicle’s specifications before ordering.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Are these Sangyue O2 sensors a direct fit for my 2005 Trailblazer 4.2L?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, this 2-piece set lists fitment for 2004–2005 Trailblazer 4.2L, but verify using the vehicle selector (make, model, year, engine) first.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does the kit include upstream and downstream sensors?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, the package contains two sensors: one upstream (pre-cat) and one downstream (post-cat).\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Sangyue","offers":[{"title":"Default Title","offer_id":48085906260126,"sku":"B08DTQJMYS","price":48.48,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/sangyue-front-packaging-oxygensensor.jpg?v=1785880336","url":"https:\/\/northtrailauto.ca\/products\/sangyue-o2-oxygen-sensor-kit-2-pack-upstream-downstream-for-2004-2005-4-2l-direct-fit-oem-wiring","provider":"North Trail Auto","version":"1.0","type":"link"}