The Walker 16403 Catalytic Converter (Ultra EPA Direct Fit) is designed for 2.5L 4-cylinder Nissan engines, specifically fitting the 2004–2006 Nissan Altima (Base, S, SL) and 2006 Nissan Sentra (SE-R, SE-R Spec V). It is a front manifold converter assembly that fits 2004-2006 2.5L Nissan Altima and 2006 2.5L Sentra, as shown in the Parts Geek 2004-2006 Nissan Altima Listing and Parts Geek 2006 Nissan Sentra Listing.


Walker Ultra Direct-Fit catalytic converters fit like OE, because the company makes original equipment! Besides the perfect fit, inside the Ultra catalytic converters are ceramic substrates with high-tech washcoat and the right loading of precious metals. The outside bodies are stainless steel for long life and durability. Catalytic converters are a vital part of your vehicle's emission control system; choose the fit, quality, and performance of a Walker Ultra catalytic converter. Order the replacement model designed for your vehicle application.