{"product_id":"o2-oxygen-sensor-upstream-downstream-for-chevrolet-tahoe-2003-2005-5-3l","title":"O2 Oxygen Sensor Upstream Downstream for Chevrolet Tahoe (2003-2005) 5.3L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Upstream \u0026amp; Downstream O2 Oxygen Sensor Kit for 2003-2005 Chevrolet Tahoe (GMT800)\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e This four-piece upstream and downstream oxygen sensor kit measures pre- and post-catalyst exhaust oxygen content on 2003-2005 \u003cstrong\u003eGMT800\u003c\/strong\u003e Chevrolet Tahoe \u003cstrong\u003eLM7 \/ L59 5.3L V8\u003c\/strong\u003e models for precise PCM fuel trim control.\u003c\/p\u003e\u003ch3\u003eThe Stock Chevrolet Tahoe Oxygen Sensor Failure\u003c\/h3\u003e\u003cp\u003eOn the \u003cstrong\u003eGMT800\u003c\/strong\u003e platform powered by the \u003cstrong\u003eLM7 \/ L59 5.3L V8\u003c\/strong\u003e, factory narrowband sensors endure severe thermal cycling and heater circuit fatigue. Carbon soot and moisture contamination foul the platinum electrodes and crack the ceramic zirconia element. As switching speed slows and heater resistance drifts, the PCM loses closed-loop fuel control, triggering \u003cstrong\u003eP0135\u003c\/strong\u003e, \u003cstrong\u003eP0155\u003c\/strong\u003e, and \u003cstrong\u003eP0171\/P0174\u003c\/strong\u003e codes.\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\u003eP0155\u003c\/strong\u003e, or false \u003cstrong\u003eP0420\/P0430\u003c\/strong\u003e catalyst codes from sluggish sensor voltage.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDelayed Closed-Loop Operation:\u003c\/strong\u003e Cold starts run overly rich, fouling spark plugs and causing raw fuel odor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePoor Economy \u0026amp; Rough Idle:\u003c\/strong\u003e Skewed fuel trims reduce towing MPG and fail OBD-II readiness monitors.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eThe Direct-Fit Zirconia O2 Sensor Solution\u003c\/h3\u003e\u003cp\u003eThis matched four-sensor kit replaces both upstream and downstream positions simultaneously to restore balanced closed-loop fueling on the \u003cstrong\u003eLM7 \/ L59 5.3L V8\u003c\/strong\u003e. Each unit uses a fast-light-off internal heater and laser-welded stainless housing that resists thermal shock and road corrosion. OEM-length harnesses and Weather Pack connectors match \u003cstrong\u003e12584925\u003c\/strong\u003e, \u003cstrong\u003e234-4342\u003c\/strong\u003e, and \u003cstrong\u003e234-4668\u003c\/strong\u003e specs for plug-and-play installation without splicing.\u003c\/p\u003e\u003ch3\u003eWhat's Included\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e2x Upstream Oxygen Sensors\u003c\/li\u003e\n\u003cli\u003e2x 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 Chevrolet Tahoe\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 V8 \/ 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; Substrate\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eEPA Federal Compliant \/ Zirconia Ceramic Element\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;\"\u003e15156, 15564, 234-4342, 234-4668, 12584925\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 Chevrolet Tahoe 5.3L V8 (2 Upstream \u0026amp; 2 Downstream)\u003c\/li\u003e\n\u003cli\u003eExcludes 4.8L V8 models, 2000-2002 Tahoe, and 2006-2007 Tahoe\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\u003ch4\u003eDoes this fit the GMT800 Tahoe?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e This is a direct fit for the 2003-2005 Chevrolet Tahoe equipped with the \u003cstrong\u003eLM7 \/ L59 5.3L V8\u003c\/strong\u003e engine. \u003cstrong\u003eExcludes the 4.8L V8 engine as well as 2000-2002 and 2006-2007 model years.\u003c\/strong\u003e\u003c\/p\u003e\u003ch4\u003eWill this clear P0135\/P0155 and P0420\/P0430 codes?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes, if faulty sensors are the cause.\u003c\/strong\u003e Restoring upstream switching and downstream monitoring resolves \u003cstrong\u003eP0135\u003c\/strong\u003e\/\u003cstrong\u003eP0155\u003c\/strong\u003e heater faults; persistent \u003cstrong\u003eP0420\/P0430\u003c\/strong\u003e codes indicate catalytic converter failure.\u003c\/p\u003e\u003ch4\u003eAre these plug-and-play, and what installation prep is needed?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e Direct-fit connectors match \u003cstrong\u003e15156\u003c\/strong\u003e, \u003cstrong\u003e15564\u003c\/strong\u003e, and \u003cstrong\u003e12584925\u003c\/strong\u003e; soak rusted bungs with penetrant, keep anti-seize off the sensor tip, and torque to spec.\u003c\/p\u003e\u003ch3\u003eThe Chevrolet Heavy-Duty Standard\u003c\/h3\u003e\u003cp\u003eEngineered for sustained exhaust heat under heavy towing loads, these matched sensors keep your \u003cstrong\u003eGMT800\u003c\/strong\u003e Tahoe in crisp closed-loop fuel trim. Restore factory throttle consistency and emissions readiness across all four banks.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":68119476404472,"sku":"DS-EZE40Z3QG","price":72.95,"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-tahoe-2003-2005-5-3l-1.jpg?v=1794723380","url":"https:\/\/performancechiptuning.com\/products\/o2-oxygen-sensor-upstream-downstream-for-chevrolet-tahoe-2003-2005-5-3l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}