{"product_id":"o2-oxygen-sensor-upstream-downstream-for-gmc-yukon-xl-1500-2003-2005-5-3l","title":"O2 Oxygen Sensor Upstream Downstream for GMC Yukon XL 1500 (2003-2005) 5.3L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit 4-Piece O2 Sensor Kit for 2003-2005 GMC Yukon XL 1500 (GMT800)\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e This 4-piece upstream and downstream oxygen sensor kit monitors exhaust air-fuel ratios and catalyst efficiency on the 2003-2005 GMC Yukon XL 1500 \u003cstrong\u003eGMT800\u003c\/strong\u003e (\u003cstrong\u003eLM7 \/ L59 5.3L\u003c\/strong\u003e).\u003c\/p\u003e\u003ch3\u003eThe Stock GMC Yukon XL 1500 Sensor Failure\u003c\/h3\u003e\u003cp\u003eFactory narrowband zirconia sensors on the \u003cstrong\u003eGMT800\u003c\/strong\u003e endure extreme thermal cycling and exhaust condensate along the \u003cstrong\u003eLM7 \/ L59 5.3L\u003c\/strong\u003e Y-pipe. Over time, ceramic elements fracture from heat soak, additives glaze platinum electrodes, and internal heaters burn out. Slowed switching strips the PCM of closed-loop fuel control, triggering \u003cstrong\u003eP0135\u003c\/strong\u003e, \u003cstrong\u003eP0141\u003c\/strong\u003e, \u003cstrong\u003eP0155\u003c\/strong\u003e, and \u003cstrong\u003eP0171\/P0174\u003c\/strong\u003e codes while hurting mileage.\u003c\/p\u003e\u003ch4\u003eCommon Symptoms of a Failing OEM Sensor\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck Engine Light:\u003c\/strong\u003e Faults like \u003cstrong\u003eP0135\u003c\/strong\u003e, \u003cstrong\u003eP0141\u003c\/strong\u003e, \u003cstrong\u003eP0155\u003c\/strong\u003e (heater), or \u003cstrong\u003eP0133\u003c\/strong\u003e (slow response).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRough Idle:\u003c\/strong\u003e Sluggish millivolt switching skews fuel trims and causes hesitation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePoor MPG:\u003c\/strong\u003e Open-loop enrichment increases fuel burn and blocks emissions readiness.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eThe Direct-Fit Oxygen Sensor Solution\u003c\/h3\u003e\u003cp\u003eReplacing all four sensors simultaneously with this matched \u003cstrong\u003e234-4668\u003c\/strong\u003e kit restores synchronized Bank 1 and Bank 2 switching across upstream and downstream bungs. Each unit uses a laser-welded stainless shield, breathable PTFE filter, and zirconia thimble to resist moisture shock. Factory-spec 4-wire harnesses and OEM weatherpack connectors plug directly into the \u003cstrong\u003eGMT800\u003c\/strong\u003e chassis loom without cutting.\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;\"\u003e2003-2005 GMC Yukon XL 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;\"\u003eLM7 \/ L59 5.3L \/ GMT800\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;\"\u003eEmissions \u0026amp; 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;\"\u003e234-4668\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003c\/div\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e2003-2005 GMC Yukon XL 1500 5.3L (2 Upstream, 2 Downstream)\u003c\/li\u003e\n\u003cli\u003eFIT FOR note: 2004-2005 Yukon, Tahoe, Silverado, Escalade 5.3L (confirm engine before ordering)\u003c\/li\u003e\n\u003cli\u003eExcludes: 2003-2006 Yukon XL 6.0L (Sheet 2828) and 2000-2002 \/ 2006 5.3L\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\u003ch4\u003eDoes this fit the GMT800 Yukon XL 1500?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e Fits 2003-2005 GMC Yukon XL 1500 with the \u003cstrong\u003eLM7 \/ L59 5.3L\u003c\/strong\u003e engine. \u003cstrong\u003eExcludes 2003-2006 6.0L (Sheet 2828) and 2000-2002 or 2006 5.3L years.\u003c\/strong\u003e\u003c\/p\u003e\u003ch4\u003eWill this clear P0135, P0141, or P0155 codes?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes, if sensors caused the fault.\u003c\/strong\u003e Replacing all four resolves open heaters and slow switching; verify wiring and exhaust gaskets near the \u003cstrong\u003e234-4668\u003c\/strong\u003e bungs.\u003c\/p\u003e\u003ch4\u003eAre connectors plug-and-play without splicing?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e All four sensors include direct-fit OEM connectors; keep tips clean and torque to spec.\u003c\/p\u003e\u003ch3\u003eThe GMC Heavy-Duty Standard\u003c\/h3\u003e\u003cp\u003eEngineered for sustained towing thermal loads on the \u003cstrong\u003eGMT800\u003c\/strong\u003e platform, this matched set maintains tight \u003cstrong\u003e5.3L\u003c\/strong\u003e closed-loop fueling and reliable emissions compliance.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":68119500488952,"sku":"DS-ESF5XFP88","price":119.95,"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-yukon-xl-1500-2003-2005-5-3l-1.jpg?v=1794724351","url":"https:\/\/performancechiptuning.com\/products\/o2-oxygen-sensor-upstream-downstream-for-gmc-yukon-xl-1500-2003-2005-5-3l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}