{"product_id":"oxygen-sensors-for-mazda-3-2004-2005-2-0l-2-3l-upstream-downstream","title":"Oxygen Sensors for Mazda 3 (2004-2005) 2.0L, 2.3L Upstream \u0026 Downstream","description":"\u003ch2\u003ePrecision-Calibrated Oxygen Sensor Kit for 2004-2005 Mazda 3\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The Oxygen Sensor Kit replaces degraded upstream and downstream lambda sensors on the 2004-2005 Mazda 3 to restore accurate closed-loop fuel metering, improve fuel economy, and clear catalytic efficiency check engine codes.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Mazda 3 Sensor Fatigue and Carbon Fouling\u003c\/h3\u003e\n\u003cp\u003eOver miles of heat cycling, the factory lambda sensors on the first-generation \u003cstrong\u003eBK\u003c\/strong\u003e chassis accumulate carbon soot, oil vapors, and thermal stress. On the naturally aspirated \u003cstrong\u003eMZR\u003c\/strong\u003e 2.0L and 2.3L platforms, sluggish switching times in the upstream sensor prevent the ECU from maintaining stoichiometric air-fuel balance. Concurrently, a degraded downstream sensor triggers false catalyst inefficiency codes (P0420) and forces the powertrain control module into altered trim strategies, which causes rough idling, reduced throttle responsiveness, and elevated tailpipe emissions.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis 2-piece sensor set delivers precision exhaust gas monitoring using fast-acting zirconia ceramic elements encased in protective 304 stainless steel housings. Equipped with internal ceramic heater elements, both upstream and downstream sensors reach operating temperature rapidly to shorten open-loop cold-start cycles. Features include direct-fit factory-keyed harness connectors, heat-resistant fiberglass lead wire sleeving, and pre-conditioned threads to guarantee simple plug-and-play installation without wire splicing or pin repinning.\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;\"\u003e2004-2005 Mazda 3\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;\"\u003e2.0L LF-DE \u0026amp; 2.3L L3-VE MZR \/ BK\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;\"\u003e148-160 hp \/ 135-150 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\u003e2004-2005 Mazda 3 i Sedan 4-Door (2.0L L4 MZR)\u003c\/li\u003e\n  \u003cli\u003e2004-2005 Mazda 3 s Sedan 4-Door (2.3L L4 MZR)\u003c\/li\u003e\n  \u003cli\u003e2004-2005 Mazda 3 s Hatchback 5-Door (2.3L L4 MZR)\u003c\/li\u003e\n  \u003cli\u003e2005 Mazda 3 SP23 Sedan \u0026amp; Hatchback (2.3L L4 MZR)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this fit the BK 3?\u003c\/strong\u003e\u003cbr\u003e Yes, this is a direct fit for the 2004-2005 Mazda 3 equipped with the 2.0L and 2.3L \u003cstrong\u003eMZR\u003c\/strong\u003e engine.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this resolve rich\/lean fuel trim trouble codes like P0171 or P0172?\u003c\/strong\u003e\u003cbr\u003e Yes, replacing slow-reacting or shorted oxygen sensors restores accurate air-fuel ratio data to the ECU, correcting fuel trim deviations and clearing related DTCs once reset.\u003c\/p\u003e\n\n\u003ch3\u003eThe Mazda Powertrain Standard\u003c\/h3\u003e\n\u003cp\u003eBuilt to meet the demands of dynamic JDM sport compacts, this replacement set restores factory engine responsiveness, optimizes combustion efficiency, and ensures clean, trouble-free operation across the rev range.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":50511134228728,"sku":"DS-ENXTY6W3F","price":79.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/oxygen-sensors-for-mazda-3-2004-2005-2-0l-2-3l-upstream-downstream-1.jpg?v=1789410572","url":"https:\/\/performancechiptuning.com\/es\/products\/oxygen-sensors-for-mazda-3-2004-2005-2-0l-2-3l-upstream-downstream","provider":"Performance Chip Tuning","version":"1.0","type":"link"}