{"product_id":"o2-oxygen-sensor-upstream-downstream-for-gmc-sierra-2500-hd-2008-2011-6-0l","title":"O2 Oxygen Sensor Upstream Downstream for GMC Sierra 2500 HD (2008-2011) 6.0L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Replacement Oxygen Sensor Kit for 2008-2011 GMC Sierra (GMT900)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The 4-Piece Oxygen Sensor Kit restores accurate closed-loop fuel monitoring on the 2008-2011 Sierra 2500 HD to optimize engine air-fuel trim ratios and clear persistent emissions fault codes.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock GMC Sierra Sensor Degradation \u0026amp; Thermal Fatigue\u003c\/h3\u003e\n\u003cp\u003eUnder heavy towing and elevated exhaust gas temperatures, factory oxygen sensors on the \u003cstrong\u003eGMT900\u003c\/strong\u003e platform suffer from gradual contamination and thermal fatigue. Exhaust soot, oil ash, and fuel additives coat the internal zirconia sensing element, causing signal lag and sensor drift. In addition, constant thermal cycling causes internal ceramic heater failure, resulting in extended open-loop operation, rough idling, excessive fuel consumption, and catalytic converter deterioration flagged by codes like P0135, P0141, or P0420.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis complete 4-piece sensor package refreshes the entire exhaust telemetry circuit with precision-calibrated planar ceramic elements. Housed in laser-welded, corrosion-resistant 304 stainless steel housings, these direct-fit sensors resist carbon fouling and thermal degradation. High-efficiency internal heating circuits achieve operating temperature in seconds, allowing the \u003cstrong\u003eVortec 6.0L (LY6\/L96)\u003c\/strong\u003e powertrain control module to quickly transition into closed-loop mode for targeted 14.7:1 stoichiometric combustion. Pre-wired factory connectors ensure seamless plug-and-play installation without cutting, splicing, or repinning OEM pigtails.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2x Upstream Oxygen (O2) Sensors\u003c\/li\u003e\n  \u003cli\u003e2x Downstream Oxygen (O2) 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;\"\u003e2008-2011 GMC Sierra\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 6.0L V8 (LY6\/L96) \/ 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;\"\u003e360 hp \/ 380 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\u003e2008-2011 GMC Sierra 2500 HD 6.0L V8\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 Sierra?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 2008-2011 GMC Sierra equipped with the \u003cstrong\u003eVortec 6.0L (LY6\/L96)\u003c\/strong\u003e engine. \u003cstrong\u003eConfirm your vehicle is equipped with the 6.0L gas V8 engine, as this kit does not fit 6.6L Duramax diesel applications.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch4\u003eAre these sensors plug-and-play or is wire splicing required?\u003c\/h4\u003e\n\u003cp\u003eAll four sensors feature factory-style direct-fit weatherproof plugs and pre-measured wire lengths for immediate bolt-on installation without wire modification.\u003c\/p\u003e\n\n\u003ch3\u003eThe GMC Heavy-Duty Standard\u003c\/h3\u003e\n\u003cp\u003eMaintaining accurate air-fuel management is vital for safeguarding exhaust components and preserving sustained hauling power under heavy gross combined vehicle weight ratings.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67551233573112,"sku":"DS-ETXFNKTZJ","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-gmc-sierra-2500-hd-2008-2011-6-0l-1.jpg?v=1790793756","url":"https:\/\/performancechiptuning.com\/products\/o2-oxygen-sensor-upstream-downstream-for-gmc-sierra-2500-hd-2008-2011-6-0l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}