{"product_id":"a-premium-upstream-downstream-oxygen-sensor-kit-for-subaru-h4-pair-4-wire-heated-direct-fit","title":"A-Premium Upstream \u0026 Downstream Oxygen Sensor Kit for Subaru H4 — Pair, 4‑Wire Heated Direct-Fit","description":"\u003cp\u003e\u003cstrong\u003eA-Premium Upstream \u0026amp; Downstream O2 Oxygen Sensor kit replaces faulty oxygen sensors on compatible Subaru H4 engines for accurate air\/fuel monitoring and restored engine performance.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis pair of heated oxygen sensors (upstream and downstream) is made to fit a range of Subaru models with H4 engines. Designed as a direct-fit replacement, the sensors include a threaded mount, 4-wire heated connectors, and factory-style lengths for plug-and-play installation. Each kit contains two boxed sensors and is backed by A-Premium’s one-year unlimited-mileage guarantee.\u003c\/p\u003e\n\n\u003ch3\u003eWhich Subaru models and engines are these sensors compatible with?\u003c\/h3\u003e\n\u003cp\u003eThe A-Premium sensors are engineered for multiple Subaru applications across model years where the listed engine types were used. They cover both upstream (pre-catalytic converter) and downstream (post-catalytic converter) positions for accurate exhaust monitoring.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSubaru Crosstrek 2016–2020 H4 2.0L\u003c\/li\u003e\n  \u003cli\u003eSubaru Forester 2013–2020 H4 2.5L (naturally aspirated)\u003c\/li\u003e\n  \u003cli\u003eSubaru Impreza 2012–2020 H4 2.0L\u003c\/li\u003e\n  \u003cli\u003eSubaru Legacy and Outback 2013–2019 H4 2.5L (DOHC)\u003c\/li\u003e\n  \u003cli\u003eXV Crosstrek 2013 \/ 2014 \/ 2015 H4 2.0L (GAS where listed)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the technical details and reference numbers I should match?\u003c\/h3\u003e\n\u003cp\u003eThese sensors are 4-wire heated units with male connectors and threaded mounting, supplied as a two-piece boxed set. Use the listed part references to confirm fit with your vehicle’s existing sensor numbers.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eWire count: 4 (heated sensor)\u003c\/li\u003e\n  \u003cli\u003eOverall cable lengths: approximately 425 mm and 400 mm\u003c\/li\u003e\n  \u003cli\u003eConnector gender: male; mounting: threaded\u003c\/li\u003e\n  \u003cli\u003eReference numbers: 350-34052, 250-24487, 250-54084, 350-64031, OS5579\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow straightforward is installation, and what tools are required?\u003c\/h3\u003e\n\u003cp\u003eInstallation is intended to be simple for anyone familiar with basic automotive maintenance. The sensors are direct-fit replacements that typically require only common hand tools — no special programming or custom wiring is necessary for most installations.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eStandard oxygen sensor socket or wrench recommended\u003c\/li\u003e\n  \u003cli\u003eHand tools: ratchet and extensions for access\u003c\/li\u003e\n  \u003cli\u003eNo soldering or splicing needed when matching factory connectors\u003c\/li\u003e\n  \u003cli\u003eAllow engine cooldown before removing old sensors for safety\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat durability and warranty support does A-Premium provide?\u003c\/h3\u003e\n\u003cp\u003eThese oxygen sensors are built from durable materials to withstand exhaust conditions and provide consistent readings. A-Premium backs the sensors with a one-year unlimited-mileage guarantee to cover functional defects, giving added confidence after purchase.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eConstructed from premium materials for long service life\u003c\/li\u003e\n  \u003cli\u003ePackaged as two boxed sensors for upstream and downstream positions\u003c\/li\u003e\n  \u003cli\u003eOne-year unlimited-mileage warranty included\u003c\/li\u003e\n  \u003cli\u003eSold as a matched pair for consistent system performance\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: This A-Premium O2 sensor kit is intended for Subaru owners, independent mechanics, and DIY enthusiasts who need a reliable upstream and downstream replacement for affected Crosstrek, Forester, Impreza, Legacy, Outback, or XV models. It suits anyone seeking a cost-effective, direct-fit sensor pair that restores proper exhaust sensing without custom modifications.\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 sensors sold as a pair or individually?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: This listing includes two sensors: one upstream and one downstream packaged together.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Do I need to program the sensors after installation?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No programming is normally required; they are direct-fit replacements with factory-style connectors.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"A-Premium","offers":[{"title":"Default Title","offer_id":55171518300503,"sku":"B0C1B8MJWM","price":77.5,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1050\/1524\/7191\/files\/a-premium-front-packaging-subaru-oxygen-sensors.jpg?v=1790447447","url":"https:\/\/britishgarage.co.uk\/products\/a-premium-upstream-downstream-oxygen-sensor-kit-for-subaru-h4-pair-4-wire-heated-direct-fit","provider":"British Garage","version":"1.0","type":"link"}