{"product_id":"exhaust-manifold-header-with-catalytic-converter-for-nissan-altima-2007-2012-2-5l","title":"Exhaust Manifold Header with Catalytic Converter for Nissan Altima (2007-2012) 2.5L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Exhaust Manifold Header with Catalytic Converter for 2007-2012 Nissan Altima (L32)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The Exhaust Manifold Header with Catalytic Converter replaces the failed factory manifold on the 2007-2012 Nissan Altima to eliminate exhaust leaks, restore accurate upstream AFR readings, and maintain EPA OBD-II emissions compliance.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Nissan Altima Manifold Cracking Problem\u003c\/h3\u003e\n\u003cp\u003eThe factory cast-iron manifold on the \u003cstrong\u003eQR25DE\u003c\/strong\u003e is notorious for structural thermal fatigue. Cyclic expansion and contraction stress the thin cast runners directly above the catalytic converter substrate, yielding hairline stress fractures near the cylinder head flange. These fractures introduce ambient oxygen ahead of the primary air-fuel ratio sensor, falsifying fuel trims, causing rough idle, and triggering false lean trouble codes (P0171, P0420). Additionally, disintegrated internal ceramic washcoat risks catastrophic cylinder back-siphon during valve overlap.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis replacement assembly eliminates cast-iron brittleness by utilizing heavy-gauge, mandrel-bent stainless steel tubular runners TIG-welded to a precision-machined, warp-resistant mounting flange. Smooth tubular geometry minimizes boundary-layer turbulence and reduces backpressure relative to rough OEM castings. The integrated high-flow ceramic substrate meets federal EPA and OBD-II monitoring parameters. Built to match OEM part numbers \u003cstrong\u003e753006\u003c\/strong\u003e, \u003cstrong\u003e40800\u003c\/strong\u003e, and \u003cstrong\u003e641302\u003c\/strong\u003e, it retains factory mounting geometry, the pre-converter O2 sensor bung, and the OEM 3-bolt lower flange connection.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1 Exhaust Manifold Header with Integrated Catalytic Converter\u003c\/li\u003e\n  \u003cli\u003eManifold and Flange Gaskets\u003c\/li\u003e\n  \u003cli\u003eExhaust Studs\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: solid font-size: min-width:\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;\"\u003e2007-2012 Nissan Altima\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;\"\u003eQR25DE \/ L32\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;\"\u003e175 hp \/ 180 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;\"\u003e753006, 40800, 641302\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\u003e2007-2012 Nissan Altima 2.5L 4-Cylinder Sedan (Base, S, SL)\u003c\/li\u003e\n  \u003cli\u003e2008-2012 Nissan Altima 2.5L 4-Cylinder Coupe (S)\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 L32 Altima?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 2007-2012 Nissan Altima equipped with the \u003cstrong\u003eQR25DE\u003c\/strong\u003e engine. \u003cstrong\u003eNon-CARB compliant; not legal for sale or use in California, Colorado, New York, or Maine on CARB emissions-equipped vehicles. Does not fit 3.5L V6 (VQ35DE) models.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch4\u003eWhat torque sequence should be used during installation?\u003c\/h4\u003e\n\u003cp\u003eClean the cylinder head mating surface completely, torque new fasteners from the center cylinders outward in two stages to prevent flange warpage, and retorque hardware following the first full thermal cycle.\u003c\/p\u003e\n\n\u003ch3\u003eThe Nissan QR Performance Standard\u003c\/h3\u003e\n\u003cp\u003eEngineered to withstand the intense thermal cycles of high-compression Japanese 4-cylinders, this manifold restores proper backpressure dynamics, eliminates exhaust cabin intrusion, and delivers clean, leak-free exhaust velocity.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67896183521528,"sku":"DS-ESQ94M27C","price":130.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/exhaust-manifold-header-with-catalytic-converter-for-nissan-altima-2007-2012-2-5l-1.jpg?v=1793293594","url":"https:\/\/performancechiptuning.com\/de\/products\/exhaust-manifold-header-with-catalytic-converter-for-nissan-altima-2007-2012-2-5l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}