AP Exhaust 644131 Catalytic Converter - Rear

Direct-Fit Catalytic Converter for Sentra

AP Exhaust Direct Fit Converter 644131 is a Federal / EPA direct-fit catalytic converter built for exact OE dimensions and fitment. It is engineered for rear-position applications on select Nissan Sentra models, with a ceramic substrate and welded 2-bolt inlet and outlet connections for a factory-style exhaust repair.

Key Features

• Federal / EPA direct-fit catalytic converter
• Ceramic substrate material
• 2-bolt welded inlet and outlet connections
• 1 O2 sensor port
• 29-inch overall length
• Inlet and outlet gaskets and hardware noted in the product design
• AP Exhaust Direct Fit Converter line focuses on OE dimensions and consistent fitment

Product Details

AP Exhaust part number 644131 uses ARISTO substrate chemistry and advanced manufacturing methods to support efficient catalyst loading while maintaining OE-style dimensions. The result is a direct-fit replacement for emissions repair work on Nissan Sentra rear exhaust applications, including 2019 Nissan Sentra, rear, California Emissions; 2013-2018 Nissan Sentra, rear, California Emissions; and 2013-2017 Nissan Sentra, N/A, California Emissions. This part cross-references Monroe Shocks & Struts (e.g., 172286) for the same application.

Common Problems This Part Can Address

• Failed catalytic converter emissions testing
• Check engine light related to catalyst efficiency
• Restricted exhaust flow from a worn converter
• Exhaust odor caused by catalyst breakdown
• Direct-fit replacement needs on Nissan Sentra rear exhaust systems

Installation Notes and Tips

Verify the vehicle’s emissions certification and rear-position application before installation. This converter uses 2-bolt welded inlet and outlet connections and includes one O2 sensor port, so confirm sensor placement and flange alignment against the original exhaust assembly. For California-emissions listings, review state and local restrictions before use.

Quality Assurance

AP Exhaust builds this converter to OE dimensions using automated workstations, spinner welding equipment, and high-speed production lines to support consistent fitment and manufacturing control. The ceramic substrate and direct-fit design are intended to deliver a factory-style replacement for the listed Nissan Sentra applications.