{"product_id":"oxygen-sensors-for-mazda-protege-2001-2003-2-0l-downstream","title":"Oxygen Sensors for Mazda Protege (2001-2003) 2.0L Downstream","description":"\u003ch2\u003eDirect-Fit Downstream Oxygen Sensor for 2001-2003 Mazda Protegé\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The downstream oxygen sensor monitors post-catalytic exhaust gas conversion on the 2001-2003 Mazda Protegé to verify catalyst efficiency and maintain closed-loop fuel trim stability.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Mazda Protegé Secondary Sensor Degradation\u003c\/h3\u003e\n\u003cp\u003eExtended thermal cycling up to 1,400°F combined with unburnt hydrocarbon and silica exposure continuously fouls the factory zirconium dioxide element. On aging \u003cstrong\u003eBJ\u003c\/strong\u003e chassis sedans, original downstream units on the \u003cstrong\u003eFS-DE\u003c\/strong\u003e engine develop high internal resistance and slow switching frequencies. This sensor latency triggers nuisance catalytic converter diagnostic trouble codes (DTCs) such as \u003cstrong\u003eP0420\u003c\/strong\u003e, \u003cstrong\u003eP0136\u003c\/strong\u003e, and \u003cstrong\u003eP0141\u003c\/strong\u003e, even when the catalyst substrate is physically intact.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis replacement downstream sensor incorporates a precision planar ceramic sensing core shielded by a 310-grade stainless steel body to defend against exhaust contamination and thermal shock. A built-in ceramic heating element decreases light-off time, allowing the ECU to evaluate downstream oxygen levels quickly upon cold start. Built to exact factory harness lengths with OEM-spec weather-sealed pin connectors and pre-conditioned M18x1.5 rolled threads, it installs cleanly without harness splicing or signal resistance issues.\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;\"\u003e2001-2003 Mazda Protegé\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\u003eFS-DE\u003c\/strong\u003e (2.0L DOHC) \/ \u003cstrong\u003eBJ\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;\"\u003e130 hp \/ 135 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\u003e2001 Mazda Protegé 2.0L L4 (Downstream)\u003c\/li\u003e\n  \u003cli\u003e2002 Mazda Protegé 2.0L L4 (Downstream)\u003c\/li\u003e\n  \u003cli\u003e2003 Mazda Protegé 2.0L L4 (Downstream)\u003c\/li\u003e\n  \u003cli\u003e2002-2003 Mazda Protegé5 2.0L L4 (Downstream)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this fit the BJ Protegé?\u003c\/strong\u003e\u003cbr\u003e Yes, this is a direct fit for the 2001-2003 Mazda Protegé equipped with the \u003cstrong\u003eFS-DE\u003c\/strong\u003e engine.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill replacing a worn downstream sensor clear my P0141 and P0420 fault codes?\u003c\/strong\u003e\u003cbr\u003e Yes, if the check engine light is caused by internal heater failure or slow secondary sensor response, replacing the unit and resetting the ECU clears the fault.\u003c\/p\u003e\n\n\u003ch3\u003eThe Mazda Tuner Standard\u003c\/h3\u003e\n\u003cp\u003eEngineered to handle high-revving naturally aspirated JDM powertrains, this sensor maintains clean post-combustion diagnostics and prevents unmetered AFR drift on modified and daily-driven platforms alike.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":50511732441336,"sku":"DS-E0LEVNK45","price":64.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/oxygen-sensors-for-mazda-protege-2001-2003-2-0l-downstream-1.jpg?v=1789418780","url":"https:\/\/performancechiptuning.com\/es\/products\/oxygen-sensors-for-mazda-protege-2001-2003-2-0l-downstream","provider":"Performance Chip Tuning","version":"1.0","type":"link"}