{"product_id":"o2-oxygen-sensor-upstream-downstream-for-nissan-altima-2004-2006-2-5l","title":"O2-Sauerstoffsensor Vorlauf und Nachlauf für Nissan Altima (2004–2006) 2,5 l","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Upstream \u0026amp; Downstream O2 Oxygen Sensor Kit for 2004-2006 Nissan Altima (L31)\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e This matched upstream air-fuel ratio and downstream oxygen sensor kit restores closed-loop fueling precision and catalyst monitoring on the 2004-2006 Nissan Altima (\u003cstrong\u003eL31\u003c\/strong\u003e) \u003cstrong\u003eQR25DE 2.5L I4\u003c\/strong\u003e.\u003c\/p\u003e\u003ch3\u003eThe Stock Nissan Altima O2 Sensor Failure\u003c\/h3\u003e\u003cp\u003eOn the \u003cstrong\u003eL31\u003c\/strong\u003e Altima with the \u003cstrong\u003eQR25DE 2.5L I4\u003c\/strong\u003e, factory oxygen sensors endure severe thermal cycling and exhaust carbon fouling. Over time, the zirconia sensing element degrades or suffers heater circuit burnout, slowing lambda response. Oil residue or coolant contamination also poisons the platinum electrodes, triggering stubborn \u003cstrong\u003eP2A00\u003c\/strong\u003e, \u003cstrong\u003eP0133\u003c\/strong\u003e, and \u003cstrong\u003eP0031\u003c\/strong\u003e codes while forcing the ECM into rich open-loop fueling.\u003c\/p\u003e\u003ch4\u003eCommon Symptoms of a Failing OEM O2 Sensor\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck Engine Light \/ DTCs:\u003c\/strong\u003e Persistent \u003cstrong\u003eP2A00\u003c\/strong\u003e, \u003cstrong\u003eP0133\u003c\/strong\u003e, or \u003cstrong\u003eP0031\u003c\/strong\u003e codes from slow sensor response or dead heaters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRich Fuel Trims:\u003c\/strong\u003e Sluggish closed-loop feedback causes fouled spark plugs and reduced fuel economy.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrivability \u0026amp; Emissions Impact:\u003c\/strong\u003e Hesitation under throttle load and failed state emissions inspections.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eThe Direct-Fit Planar Zirconia Sensor Solution\u003c\/h3\u003e\u003cp\u003eReplacing both sensors together restores balanced exhaust feedback across the \u003cstrong\u003eL31\u003c\/strong\u003e exhaust stream. This matched kit pairs one upstream air-fuel ratio sensor with one downstream heated oxygen sensor featuring fast-light-off heaters and stainless housings. Factory-length harnesses and OEM-style weatherproof connectors plug directly into the \u003cstrong\u003eQR25DE 2.5L I4\u003c\/strong\u003e loom without splicing. Precision-cut threads ensure clean bolt-on seating in stock exhaust bungs.\u003c\/p\u003e\u003ch3\u003eWhat's Included\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e1 Upstream Air-Fuel Ratio Oxygen Sensor\u003c\/li\u003e\n\u003cli\u003e1 Downstream Heated Oxygen Sensor\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px; min-width: 300px;\"\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eFitment\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e2004-2006 Nissan Altima\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eEngine \/ Chassis\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eQR25DE 2.5L I4 \/ L31\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eSensor Architecture\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eUpstream Air-Fuel Ratio (A\/F) \u0026amp; Downstream Heated O2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eInstallation Type\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eDirect Bolt-On OEM Replacement (No Cutting or Welding)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003c\/div\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e2004-2006 Nissan Altima 2.5L (\u003cstrong\u003eQR25DE 2.5L I4\u003c\/strong\u003e — Upstream \u0026amp; Downstream Positions)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\u003ch4\u003eDoes this fit the L31 Altima?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e Fits 2004-2006 Nissan Altima \u003cstrong\u003eQR25DE 2.5L I4\u003c\/strong\u003e models. \u003cstrong\u003eExcludes 3.5L V6 Altima and Sentra 2.5L; confirm engine before ordering.\u003c\/strong\u003e\u003c\/p\u003e\u003ch4\u003eWill this clear P2A00, P0133, or P0031 codes?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e Replacing failed sensors restores ECM lambda feedback and heater resistance to resolve \u003cstrong\u003eP2A00\u003c\/strong\u003e, \u003cstrong\u003eP0133\u003c\/strong\u003e, and \u003cstrong\u003eP0031\u003c\/strong\u003e after resetting codes.\u003c\/p\u003e\u003ch4\u003eIs wiring splicing required during installation?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eNo.\u003c\/strong\u003e Both sensors include OEM-style plug-and-play connectors for direct installation into factory exhaust bungs with no cutting or splicing.\u003c\/p\u003e\u003ch3\u003eThe Nissan Precision Standard\u003c\/h3\u003e\u003cp\u003eBuilt for JDM durability, this matched set restores crisp throttle response and closed-loop efficiency, keeping your \u003cstrong\u003eL31\u003c\/strong\u003e \u003cstrong\u003eQR25DE 2.5L I4\u003c\/strong\u003e emissions-compliant and CEL-free.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":68119395565816,"sku":"DS-E6DX6N5LK","price":78.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/o2-oxygen-sensor-upstream-downstream-for-nissan-altima-2004-2006-2-5l-1.jpg?v=1794719881","url":"https:\/\/performancechiptuning.com\/de\/products\/o2-oxygen-sensor-upstream-downstream-for-nissan-altima-2004-2006-2-5l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}