{"product_id":"o2-oxygen-sensor-upstream-downstream-for-subaru-impreza-forester-legacy-outback-2006-2009-2-5l","title":"O2 Oxygen Sensor Upstream Downstream for Subaru Impreza, Forester, Legacy, Outback (2006-2009) 2.5L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit O2 Oxygen Sensor Set for 2006-2009 Subaru Impreza, Forester, Legacy, Outback (GD, SG, BL, BP)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The Upstream and Downstream O2 Sensor Set replaces degraded exhaust gas sensors on 2006-2009 Subaru 2.5L vehicles to restore factory air-fuel closed-loop feedback, resolve diagnostic trouble codes, and stabilize idle trim.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Subaru Impreza, Forester, Legacy, Outback Sensor Contamination and Thermal Fatigue\u003c\/h3\u003e\n\u003cp\u003eOver extended thermal cycles, the factory zirconia ceramic sensing elements in the \u003cstrong\u003eEJ253\u003c\/strong\u003e exhaust stream suffer severe silica, carbon, and oil vapor contamination. On chassis platforms like the \u003cstrong\u003eGD\/GE\u003c\/strong\u003e Impreza, \u003cstrong\u003eSG\/SH\u003c\/strong\u003e Forester, and \u003cstrong\u003eBL\/BP\u003c\/strong\u003e Legacy\/Outback, aging upstream air-fuel ratio sensors (A\/F) exhibit signal latency and drifted output voltage. This latency forces the ECM into rich or lean bias, causing catalyst inefficiency codes (\u003cstrong\u003eP0420\u003c\/strong\u003e, \u003cstrong\u003eP0430\u003c\/strong\u003e), circuit faults (\u003cstrong\u003eP0130\u003c\/strong\u003e through \u003cstrong\u003eP0161\u003c\/strong\u003e), catalytic converter damage, rough cold idle, and elevated hydrocarbon emissions.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eEngineered to precise OEM specifications, this complete pre- and post-catalyst sensor pair features double-protection stainless steel housings that resist exhaust gas particulate erosion and thermal shock. The high-speed ceramic sensing elements deliver rapid response times, allowing the factory ECU to dynamically regulate stoichiometric fueling (14.7:1 AFR) across all load ranges. Pre-crimped harness terminals, factory-matched wiring loom lengths, and OEM waterproof connectors guarantee plug-and-play installation into factory bungs without wire slicing, terminal pinning, or resistance errors.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1 Upstream Oxygen (A\/F) Sensor\u003c\/li\u003e\n  \u003cli\u003e1 Downstream Oxygen Sensor\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: solid font-size: min-width:\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;\"\u003e2006-2009 Subaru Impreza, Forester, Legacy, Outback\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;\"\u003eEJ253 2.5L SOHC \/ GD, GE, GG, GH, SG, SH, BL, BP\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;\"\u003e170 hp \/ 170 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;\"\u003e234-4445, 234-9123, 2349123, 22641AA360, 22641AA36A, 32010412, 2133941, 15169, 15171, 753718, 753720, 24696\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\u003e2006-2009 Subaru Impreza 2.5L (Naturally Aspirated)\u003c\/li\u003e\n  \u003cli\u003e2006-2009 Subaru Forester 2.5L (Naturally Aspirated)\u003c\/li\u003e\n  \u003cli\u003e2006-2009 Subaru Legacy 2.5L (Naturally Aspirated)\u003c\/li\u003e\n  \u003cli\u003e2006-2009 Subaru Outback 2.5L (Naturally Aspirated)\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 BL\/BP, SG\/SH, and GD\/GE Impreza, Forester, Legacy, Outback?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for 2006-2009 models equipped with the naturally aspirated \u003cstrong\u003eEJ253\u003c\/strong\u003e 2.5L engine; it does not fit turbocharged EJ255 or EJ257 models.\u003c\/p\u003e\n\n\u003ch4\u003eShould anti-seize be applied during installation?\u003c\/h4\u003e\n\u003cp\u003eApply high-temperature anti-seize sparingly to the sensor threads only, ensuring none touches the protective perforated sensing tip to prevent immediate element contamination.\u003c\/p\u003e\n\n\u003ch3\u003eThe Subaru Boxer Calibration Standard\u003c\/h3\u003e\n\u003cp\u003ePreserve boxer engine response, restore closed-loop fuel economy, and eliminate persistent CEL indicators with exact-voltage feedback engineered for naturally aspirated EJ-series performance.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67910911492344,"sku":"DS-EDFXHYH4D","price":90.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/o2-15464746090744-main-clean.jpg?v=1793395742","url":"https:\/\/performancechiptuning.com\/es\/products\/o2-oxygen-sensor-upstream-downstream-for-subaru-impreza-forester-legacy-outback-2006-2009-2-5l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}