{"product_id":"oxygen-sensors-for-toyota-4runner-2003-2004-4-0l-upstream-downstream","title":"Oxygen Sensors for Toyota 4Runner (2003-2004) 4.0L Upstream \u0026 Downstream","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Oxygen Sensor Set for 2003-2004 Toyota 4Runner (N210)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The complete 4-piece oxygen sensor kit monitors exhaust gas chemistry on the 2003-2004 Toyota 4Runner to restore precise closed-loop fuel trim mapping and eliminate catalyst efficiency diagnostic trouble codes.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Toyota 4Runner Sensor Degradation\u003c\/h3\u003e\n\u003cp\u003eFactory air-fuel ratio and zirconia oxygen sensors on the fourth-generation \u003cstrong\u003eN210\u003c\/strong\u003e platform suffer from internal ceramic element contamination and thermal fatigue after thousands of heat cycles. As silicone deposits, carbon soot, and fuel additives coat the sensing thimble, response latency increases. On the \u003cstrong\u003e1GR-FE\u003c\/strong\u003e 4.0L V6, this sluggish sensor transition forces the engine control module into erratic short-term fuel trims, leading to sub-optimal stoichiometry, rich-condition spark plug fouling, decreased fuel economy, and diagnostic trouble codes such as P0130, P0161, P0420, and P0430.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis replacement set delivers four matched, pre-calibrated sensors engineered to restore factory signal integrity across both exhaust banks. Featuring platinum-electroplated ceramic planar elements inside double-laser-welded stainless steel protective sheaths, these sensors resist thermal shock and exhaust particulate poisoning. Pre-applied high-temperature anti-seize compound prevents thread galling in the factory cast-iron bungs. Factory-spec wiring harnesses, heat-resistant fiberglass sleeving, and OE-keyed 4-pin weather-pack connectors ensure exact plug-and-play installation without wire splicing or circuit resistance variation.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2x Upstream Oxygen \/ Air-Fuel Ratio Sensors\u003c\/li\u003e\n  \u003cli\u003e2x Downstream Oxygen Sensors\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\n  \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;\"\u003e2003-2004 Toyota 4Runner\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\u003e1GR-FE\u003c\/strong\u003e (4.0L V6) \/ \u003cstrong\u003eN210\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;\"\u003e245 hp \/ 282 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;\"\u003e\n\u003cstrong\u003e234-9047\u003c\/strong\u003e, \u003cstrong\u003e234-4804\u003c\/strong\u003e, \u003cstrong\u003e234-4805\u003c\/strong\u003e, \u003cstrong\u003e89467-60010\u003c\/strong\u003e, \u003cstrong\u003e89465-60220\u003c\/strong\u003e, \u003cstrong\u003e89465-60230\u003c\/strong\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2003 Toyota 4Runner 4.0L V6 (SR5, Limited, Sport Edition)\u003c\/li\u003e\n  \u003cli\u003e2004 Toyota 4Runner 4.0L V6 (SR5, Limited, Sport Edition)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\n\u003ch4\u003eDoes this fit the N210 4Runner?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 2003-2004 Toyota 4Runner equipped with the \u003cstrong\u003e1GR-FE\u003c\/strong\u003e 4.0L V6 engine. \u003cstrong\u003eThis set is not compatible with models equipped with the 4.7L 2UZ-FE V8 engine.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch4\u003eDo I need special tools to complete the installation?\u003c\/h4\u003e\n\u003cp\u003eA slotted 7\/8-inch (22mm) oxygen sensor socket or offset flare wrench is recommended to clear the harness while breaking the factory sensors loose from exhaust bungs.\u003c\/p\u003e\n\n\u003ch3\u003eThe Toyota Durability Standard\u003c\/h3\u003e\n\u003cp\u003eRestoring closed-loop fuel management on the \u003cstrong\u003eN210\u003c\/strong\u003e 4Runner maintains continuous combustion efficiency, protecting your catalytic converters and preserving the robust off-road crawling and towing reliability built into the 4.0L platform.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67895978688760,"sku":"DS-E991GIORX","price":127.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/oxygen-sensors-for-toyota-4runner-2003-2004-4-0l-upstream-downstream-1.jpg?v=1793290032","url":"https:\/\/performancechiptuning.com\/products\/oxygen-sensors-for-toyota-4runner-2003-2004-4-0l-upstream-downstream","provider":"Performance Chip Tuning","version":"1.0","type":"link"}