{"product_id":"o2-oxygen-sensor-upstream-downstream-for-gmc-sierra-2008-2013-4-3l","title":"O2 Oxygen Sensor Upstream Downstream for GMC Sierra (2008-2013) 4.3L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit O2 Oxygen Sensor Kit for 2008-2013 GMC Sierra (GMT900)\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e This upstream and downstream O2 sensor kit monitors exhaust oxygen levels on the 2008-2013 GMC Sierra (\u003cstrong\u003eGMT900\u003c\/strong\u003e) \u003cstrong\u003eLU3 4.3L V6\u003c\/strong\u003e for ECM fuel trim control.\u003c\/p\u003e\u003ch3\u003eThe Stock GMC Sierra Oxygen Sensor Failure\u003c\/h3\u003e\u003cp\u003eOn high-mileage \u003cstrong\u003eGMT900\u003c\/strong\u003e trucks with the \u003cstrong\u003eLU3 4.3L V6\u003c\/strong\u003e, OEM oxygen sensors suffer from thermal cycling fatigue, carbon fouling, and heater circuit degradation. As the zirconia element ages, voltage switching slows and skews closed-loop fuel trim toward rich or lean drift. Exhaust heat soak and moisture intrusion also fracture internal heaters, triggering \u003cstrong\u003eP0135\u003c\/strong\u003e, \u003cstrong\u003eP0141\u003c\/strong\u003e, \u003cstrong\u003eP0155\u003c\/strong\u003e, and \u003cstrong\u003eP0161\u003c\/strong\u003e alongside sluggish response codes like \u003cstrong\u003eP0133\u003c\/strong\u003e or \u003cstrong\u003eP0171\/P0174\u003c\/strong\u003e.\u003c\/p\u003e\u003ch4\u003eCommon Symptoms of a Failing OEM Oxygen Sensor\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck Engine Light \/ DTCs:\u003c\/strong\u003e Triggers \u003cstrong\u003eP0135\u003c\/strong\u003e, \u003cstrong\u003eP0141\u003c\/strong\u003e, \u003cstrong\u003eP0171\/P0174\u003c\/strong\u003e, or false \u003cstrong\u003eP0420\u003c\/strong\u003e codes from slow switching.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRough Idle \u0026amp; Hesitation:\u003c\/strong\u003e Delayed millivolt feedback disrupts closed-loop fueling under light load.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePoor MPG \u0026amp; Emissions Failure:\u003c\/strong\u003e Rich open-loop defaulting increases fuel use and fails readiness tests.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eThe Direct-Fit Heated Zirconia Solution\u003c\/h3\u003e\u003cp\u003eEngineered to match OEM numbers \u003cstrong\u003e234-4337\u003c\/strong\u003e and \u003cstrong\u003e234-4258\u003c\/strong\u003e, this 4-sensor kit restores crisp closed-loop feedback across both upstream and downstream banks. Each unit pairs a fast-acting heated zirconia element with a corrosion-resistant stainless steel housing built for extreme exhaust heat cycles. Factory-style weatherproof connectors and OEM-spec threads provide plug-and-play installation with zero wire splicing or harness modification.\u003c\/p\u003e\u003ch3\u003eWhat's Included\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e2 Upstream Oxygen Sensors\u003c\/li\u003e\n\u003cli\u003e2 Downstream Oxygen Sensors\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\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 GMC Sierra 1500\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;\"\u003eLU3 4.3L V6 \/ 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;\"\u003eSensor Architecture\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e4-Wire Heated Zirconia (Upstream \u0026amp; Downstream)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eInstallation Type\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eDirect Bolt-On OEM Replacement (No Cutting or Welding)\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;\"\u003eReplaces OEM Part #\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e234-4337, 234-4258\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003c\/div\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e2008-2013 GMC Sierra 1500 (4.3L V6 Only)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\u003ch4\u003eDoes this fit the GMT900 Sierra?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e Fits 2008-2013 GMC Sierra 1500 with the \u003cstrong\u003eLU3 4.3L V6\u003c\/strong\u003e. \u003cstrong\u003eExcludes 4.8L, 5.3L, 6.0L, and 6.2L V8 engines; confirm engine before ordering.\u003c\/strong\u003e\u003c\/p\u003e\u003ch4\u003eWill this clear O2 heater and fuel trim codes?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e Replacing all four sensors restores heater resistance and switching speed, clearing sensor-related \u003cstrong\u003eP0135\u003c\/strong\u003e, \u003cstrong\u003eP0141\u003c\/strong\u003e, and \u003cstrong\u003eP0171\/P0174\u003c\/strong\u003e codes after ECM reset.\u003c\/p\u003e\u003ch4\u003eIs wire splicing required for installation?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eNo.\u003c\/strong\u003e Each sensor includes direct-fit factory plugs for bolt-in installation; verify exhaust flanges are leak-free before clearing codes.\u003c\/p\u003e\u003ch3\u003eThe GMC Heavy-Duty Standard\u003c\/h3\u003e\u003cp\u003eBuilt for the thermal loads of daily hauling on the \u003cstrong\u003eGMT900\u003c\/strong\u003e platform, this matched sensor kit keeps your \u003cstrong\u003eLU3 4.3L V6\u003c\/strong\u003e operating at peak combustion efficiency and emissions readiness.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":68116028555512,"sku":"DS-EHFS1BX6F","price":131.95,"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-2008-2013-4-3l-1.jpg?v=1794710399","url":"https:\/\/performancechiptuning.com\/products\/o2-oxygen-sensor-upstream-downstream-for-gmc-sierra-2008-2013-4-3l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}