{"product_id":"catalytic-converter-for-nissan-altima-2013-2018-2-5l-front","title":"Catalytic Converter for Nissan Altima (2013-2018) 2.5L Front","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Front Exhaust Manifold Catalytic Converter for 2013-2018 Nissan Altima (L33)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The front catalytic converter manifold replaces degraded factory emissions equipment on the 2013-2018 Altima to eliminate P0420 fault codes, normalize exhaust scavenging, and restore factory tailpipe emissions compliance.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Nissan Altima Ceramic Washcoat Breakdown\u003c\/h3\u003e\n\u003cp\u003eThe factory integrated manifold converter on the \u003cstrong\u003eL33\u003c\/strong\u003e generation Altima faces chronic thermal cycling stress. Positioned directly against the cylinder head exhaust ports, the factory manifold suffers sustained thermal loading that degrades the internal washcoat and fractures brittle honeycomb walls. Over time, physical substrate erosion triggers downstream O2 sensor divergence, illuminating check engine warnings (P0420) while elevated exhaust backpressure chokes cylinder evacuation on the \u003cstrong\u003eQR25DE\u003c\/strong\u003e platform.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eConstructed from high-grade stainless steel with precision-cut laser flanges, this direct-fit front manifold converter eliminates exhaust leaks and resists high-heat oxidation. Inside, a durable ceramic substrate loaded with precious metal washcoat optimizes catalytic conversion efficiency without choking exhaust flow. Featuring factory-located oxygen sensor bungs and heavy-gauge mounting brackets, this unit installs directly onto the cylinder head without cutting or welding, fully interfacing with OEM hardware references \u003cstrong\u003e16694\u003c\/strong\u003e, \u003cstrong\u003e641427\u003c\/strong\u003e, \u003cstrong\u003e40989\u003c\/strong\u003e, and \u003cstrong\u003e674-149\u003c\/strong\u003e.\u003c\/p\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: 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;\"\u003e2013-2018 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 \/ L33\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;\"\u003e182 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;\"\u003e16694, 641427, 40989, 674-149\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\u003e2013 Nissan Altima Sedan 2.5L I4 (Base, S, SV, SL)\u003c\/li\u003e\n  \u003cli\u003e2014 Nissan Altima Sedan 2.5L I4 (Base, S, SV, SL)\u003c\/li\u003e\n  \u003cli\u003e2015 Nissan Altima Sedan 2.5L I4 (Base, S, SV, SL)\u003c\/li\u003e\n  \u003cli\u003e2016 Nissan Altima Sedan 2.5L I4 (Base, S, SR, SV, SL)\u003c\/li\u003e\n  \u003cli\u003e2017 Nissan Altima Sedan 2.5L I4 (Base, S, SR, SV, SL)\u003c\/li\u003e\n  \u003cli\u003e2018 Nissan Altima Sedan 2.5L I4 (S, SR, SV, SL)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eDoes this fit the L33 Altima?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 2013-2018 Nissan Altima equipped with the QR25DE engine.\u003c\/p\u003e\n\n\u003ch4\u003eWill this direct-fit converter clear a P0420 diagnostic code?\u003c\/h4\u003e\n\u003cp\u003eYes, renewing degraded catalyst substrate with this assembly restores required conversion efficiency and clears catalytic threshold diagnostic trouble codes.\u003c\/p\u003e\n\n\u003ch3\u003eThe Nissan Operational Caliber\u003c\/h3\u003e\n\u003cp\u003eEngineered for high-mileage reliability, this manifold maintains optimal backpressure balance and factory O2 sensor feedback to ensure clean tailpipe emissions and smooth throttle delivery across everyday driving conditions.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67538033115384,"sku":"DS-EN4PI9CNS","price":137.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/catalytic-converter-for-nissan-altima-2013-2018-2-5l-front-1.jpg?v=1790621183","url":"https:\/\/performancechiptuning.com\/products\/catalytic-converter-for-nissan-altima-2013-2018-2-5l-front","provider":"Performance Chip Tuning","version":"1.0","type":"link"}