{"product_id":"catalytic-converter-for-jaguar-xjr-2004-2009-4-2l","title":"Catalytic Converter for Jaguar XJR (2004-2009) 4.2L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Dual Catalytic Converter Set for 2004-2009 Jaguar XJR (X350)\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e This direct-fit dual catalytic converter set replaces both factory bank converters on the 2004-2009 Jaguar XJR (\u003cstrong\u003eX350\u003c\/strong\u003e) equipped with the \u003cstrong\u003eAJ33S\/AJ34S 4.2L Supercharged V8\u003c\/strong\u003e to restore exhaust flow and convert HC, CO, and NOx emissions.\u003c\/p\u003e\u003ch3\u003eThe Stock Jaguar XJR Catalyst Failure\u003c\/h3\u003e\u003cp\u003eOn the \u003cstrong\u003eX350\u003c\/strong\u003e chassis powered by the supercharged \u003cstrong\u003eAJ33S\/AJ34S 4.2L Supercharged V8\u003c\/strong\u003e, high exhaust gas temperatures under boost subject the factory catalytic converters to severe thermal cycling. Over time, thermal fatigue and rich-condition heat soak fracture the OEM ceramic substrate and degrade the precious-metal washcoat. Once the internal monolith breaks loose or partially melts, exhaust flow becomes restricted and downstream oxygen sensors detect oxygen storage loss, triggering \u003cstrong\u003eP0420\u003c\/strong\u003e or \u003cstrong\u003eP0430\u003c\/strong\u003e catalyst-efficiency faults.\u003c\/p\u003e\u003ch4\u003eCommon Symptoms of a Failing OEM Catalytic Converter\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck Engine Light \/ DTCs:\u003c\/strong\u003e Triggers \u003cstrong\u003eP0420\u003c\/strong\u003e (Bank 1) or \u003cstrong\u003eP0430\u003c\/strong\u003e (Bank 2) catalyst system efficiency below threshold codes when washcoat oxygen storage fails.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetallic Exhaust Rattle:\u003c\/strong\u003e Audible rattling or buzzing beneath the floorpan at idle and deceleration caused by a fractured ceramic core vibrating inside the canister.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExhaust Backpressure \u0026amp; Emissions Failure:\u003c\/strong\u003e Restricted substrate channels choke supercharged V8 exhaust scavenging, reducing top-end power and causing failed OBD-II readiness or tailpipe emissions tests.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eThe Direct-Fit Stainless Exhaust Solution\u003c\/h3\u003e\u003cp\u003eEngineered as a complete pair, these replacement converter pipes feature corrosion-resistant \u003cstrong\u003estainless steel\u003c\/strong\u003e bodies and tubing built to withstand supercharged exhaust heat without cracking. Each unit houses a high-efficiency \u003cstrong\u003eceramic honeycomb substrate\u003c\/strong\u003e coated with precious metals to restore proper HC, CO, and NOx conversion for \u003cstrong\u003eOBD-II\u003c\/strong\u003e compliance. Factory-style flanges and precision-welded O2 sensor bungs ensure an exact bolt-on fit (8-inch body length, 5-inch height) with zero cutting or welding required.\u003c\/p\u003e\u003ch3\u003eWhat's Included\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e2 x Catalytic Converter Pipes\u003c\/li\u003e\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;\"\u003e2004-2009 Jaguar XJR\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;\"\u003eAJ33S \/ AJ34S 4.2L Supercharged V8 \/ X350\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 (46-State Legal) \/ Ceramic Honeycomb\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\u003c\/table\u003e\u003c\/div\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e2004 Jaguar XJR 4.2L Supercharged V8\u003c\/li\u003e\n\u003cli\u003e2005 Jaguar XJR 4.2L Supercharged V8\u003c\/li\u003e\n\u003cli\u003e2006 Jaguar XJR 4.2L Supercharged V8\u003c\/li\u003e\n\u003cli\u003e2007 Jaguar XJR 4.2L Supercharged V8\u003c\/li\u003e\n\u003cli\u003e2008 Jaguar XJR 4.2L Supercharged V8\u003c\/li\u003e\n\u003cli\u003e2009 Jaguar XJR 4.2L Supercharged V8\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\u003ch4\u003eDoes this fit the X350 XJR?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e This is a direct fit for the 2004-2009 Jaguar XJR equipped with the \u003cstrong\u003eAJ33S\/AJ34S 4.2L Supercharged V8\u003c\/strong\u003e engine. \u003cstrong\u003eDoes not fit 2010+ XJR 5.0L models. This is an EPA federal converter and is not CARB approved—not legal for vehicles registered in California, New York, Colorado, or Maine.\u003c\/strong\u003e\u003c\/p\u003e\u003ch4\u003eWill this clear P0420\/P0430 codes, and are O2 sensors included?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes, if the fault stems from failed catalysts; oxygen sensors are not included.\u003c\/strong\u003e Replacing both degraded converters restores proper oxygen storage capacity to clear \u003cstrong\u003eP0420\u003c\/strong\u003e and \u003cstrong\u003eP0430\u003c\/strong\u003e codes, provided you transfer functional factory O2 sensors (or install new ones) and verify zero upstream exhaust leaks.\u003c\/p\u003e\u003ch4\u003eWhat preparation is required for bolt-on installation?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eAllow the exhaust to cool completely and soak all flange fasteners with penetrating oil beforehand.\u003c\/strong\u003e Unbolt the factory converter pipes, install both new units using new flange gaskets, torque all fasteners evenly, and inspect every joint for leaks at startup; professional installation is recommended.\u003c\/p\u003e\u003ch3\u003eThe Jaguar Precision Standard\u003c\/h3\u003e\u003cp\u003eMaintaining emissions compliance and crisp supercharged response on the \u003cstrong\u003eX350\u003c\/strong\u003e platform demands exact-fit exhaust components engineered for factory ECU tolerances. Installing both stainless converter pipes together restores balanced bank-to-bank backpressure and ensures trouble-free, CEL-free operation.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":68083808927992,"sku":"DS-EXWKCQMNQ","price":256.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/catalytic-converter-for-jaguar-xjr-2004-2009-4-2l-1.jpg?v=1794533558","url":"https:\/\/performancechiptuning.com\/products\/catalytic-converter-for-jaguar-xjr-2004-2009-4-2l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}