{"product_id":"o2-oxygen-sensor-upstream-downstream-for-chevrolet-avalanche-2008-2013-5-3l","title":"O2 Oxygen Sensor Upstream Downstream for Chevrolet Avalanche (2008-2013) 5.3L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Upstream \u0026amp; Downstream O2 Sensor Set for 2008-2013 Chevrolet Avalanche (GMT900)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The 4-piece oxygen sensor kit monitors exhaust gas oxygen content on the 2008-2013 Chevrolet Avalanche to correct air-fuel mixture trims and maintain catalytic converter efficiency.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Chevrolet Avalanche Sensor Degradation\u003c\/h3\u003e\n\u003cp\u003eFactory zirconia O2 sensors on the \u003cstrong\u003eGMT900\u003c\/strong\u003e platform endure persistent thermal cycling, carbon contamination, and oil blow-by over high mileage. As internal ceramic elements age, response times lag significantly, skewing short- and long-term fuel trims (STFT\/LTFT). This sluggish closed-loop feedback forces the engine control module to default to rich AFR mappings, triggering P0135, P0155, or catalyst efficiency codes (P0420, P0430), while drastically diminishing fuel economy under payload.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis 4-sensor replacement set restores closed-loop engine management precision for the \u003cstrong\u003eVortec 5.3L (LMG\/LY5\/LC9)\u003c\/strong\u003e engine. Utilizing rapid-heating ceramic planar substrates and dual-layer porous stainless-steel particulate shielding, these sensors resist fouling and premature element degradation. High-temperature fluoropolymer wiring harnesses and pre-treated threads with anti-seize ensure robust thermal protection against exhaust manifold heat soak and facilitate a seamless, direct-thread installation.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2x Upstream Oxygen 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;\"\u003e2008-2013 Chevrolet Avalanche\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;\"\u003eVortec 5.3L V8 \/ GMT900\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;\"\u003e320 hp \/ 335 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;\"\u003e21546, 234-4254, 234-4407, 234-4668, 15284, 2344254, 2344668, ES20013, OS1656, OS2239, OS2240, OS2249, SG1857\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\u003e2008-2013 Chevrolet Avalanche (5.3L V8 Engine)\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 GMT900 Avalanche?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 2008-2013 Chevrolet Avalanche equipped with the \u003cstrong\u003eVortec 5.3L\u003c\/strong\u003e engine; confirm your vehicle is equipped with the 5.3L displacement prior to ordering as it is not configured for 6.0L variants.\u003c\/p\u003e\n\n\u003ch4\u003eDo I need special tools or an ECU recalibration after installation?\u003c\/h4\u003e\n\u003cp\u003eNo calibration tune is required, but a standard 7\/8-inch (22mm) slotted O2 sensor socket is recommended along with a diagnostic scanner to reset stored fuel trim adaptations.\u003c\/p\u003e\n\n\u003ch3\u003eThe Chevrolet Truck Durability Standard\u003c\/h3\u003e\n\u003cp\u003eEngineered to handle heavy-duty hauling, towing payloads, and harsh road environments, this sensor set ensures stable lambda measurement and dependable powertrain operation on your Chevy truck.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67551205261560,"sku":"DS-EQ5KASIHN","price":79.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/o2-oxygen-sensor-upstream-downstream-for-chevrolet-avalanche-2008-2013-5-3l-1.jpg?v=1790793472","url":"https:\/\/performancechiptuning.com\/fr\/products\/o2-oxygen-sensor-upstream-downstream-for-chevrolet-avalanche-2008-2013-5-3l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}