{"product_id":"oxygen-sensors-for-nissan-altima-maxima-2002-2003-2-5l-upstream","title":"Oxygen Sensors for Nissan Altima Maxima (2002-2003) 2.5L Upstream","description":"\u003ch2\u003eDirect-Fit Upstream Oxygen Sensor for 2002-2003 Nissan Altima,Maxima\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The Upstream Oxygen Sensor replaces degraded factory air-fuel monitors on 2002-2003 Nissan Altima and Maxima 2.5L models to restore closed-loop engine management, accurate stoichiometric fueling, and stable idle dynamics.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Nissan Altima,Maxima Sensor Degradation\u003c\/h3\u003e\n\u003cp\u003eOver thousands of heat cycles, factory zirconia elements in the \u003cstrong\u003eL31\u003c\/strong\u003e and \u003cstrong\u003eA33\u003c\/strong\u003e chassis suffer from severe exhaust soot contamination, silica fouling, and thermal degradation of the internal heater circuit. As the factory sensor ages, its latency increases, causing sluggish air-fuel adjustments. This degradation leads to persistent rich or lean operating conditions, engine hesitation, increased fuel consumption, rough idle hunting, and premature wear on the catalytic converter.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eEngineered as a direct OE-style replacement, this upstream sensor utilizes an advanced planar ceramic sensing element protected by a dual-layer 304 stainless steel body to resist high exhaust gas temperatures and abrasive soot. Designed for rapid thermal light-off, the integrated rapid-heating element ensures the \u003cstrong\u003eQR25DE\u003c\/strong\u003e engine management system achieves closed-loop operation within seconds of startup. Precision-engineered harness connections and pre-conditioned threads allow for seamless installation without splicing, delivering instant, stable voltage feedback to the engine control module.\u003c\/p\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px; margin-bottom: 20px;\"\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;\"\u003e2002-2003 Nissan Altima,Maxima\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;\"\u003e\n\u003cstrong\u003eQR25DE\u003c\/strong\u003e \/ \u003cstrong\u003eL31\u003c\/strong\u003e, \u003cstrong\u003eA33\u003c\/strong\u003e\n\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;\"\u003eStock Output\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e175 hp \/ 180 lb-ft\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eReplaces OEM Part #\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eN\/A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2002-2003 Nissan Altima (2.5L 4-Cylinder QR25DE - Upstream)\u003c\/li\u003e\n  \u003cli\u003e2002-2003 Nissan Maxima (2.5L 4-Cylinder - Upstream)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this fit the L31 and A33 Altima,Maxima?\u003c\/strong\u003e\u003cbr\u003e Yes, this is a direct fit for the 2002-2003 Nissan Altima,Maxima equipped with the \u003cstrong\u003eQR25DE\u003c\/strong\u003e engine in the upstream position.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this sensor clear an active P0130 to P0135 check engine light?\u003c\/strong\u003e\u003cbr\u003e Yes, once installed with proper thread torque, clearing existing codes and completing an OBD-II drive cycle will resolve upstream sensor-related faults.\u003c\/p\u003e\n\n\u003ch3\u003eThe Nissan Powertrain Caliber\u003c\/h3\u003e\n\u003cp\u003eJDM-engineered four-cylinder powerplants depend on ultra-precise air-fuel feedback to balance peak torque output with emission compliance. Maintaining tight sensor tolerances safeguards your engine against detonation and ensures smooth, consistent throttle response across the entire rev range.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":50511715959032,"sku":"DS-EFU6VU9IC","price":69.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/oxygen-sensors-for-nissan-altima-maxima-2002-2003-2-5l-upstream-1.jpg?v=1789418306","url":"https:\/\/performancechiptuning.com\/es\/products\/oxygen-sensors-for-nissan-altima-maxima-2002-2003-2-5l-upstream","provider":"Performance Chip Tuning","version":"1.0","type":"link"}