AP Exhaust 644040 Catalytic Converter - Center or Rear

Direct-Fit Catalytic Converter for Mazda CX-5

AP Exhaust Direct Fit Converter 644040 is a Federal / EPA direct-fit catalytic converter built for specific Mazda CX-5 applications. It uses stainless steel body construction and an OE-matched layout to support proper exhaust flow, emissions control, and factory-style fitment on listed vehicles.

The AP Exhaust Direct Fit Converter line focuses on OE dimensions and consistent installation fit. For Mazda CX-5 owners, that means a replacement catalytic converter engineered around the original exhaust configuration, with attention to fitment accuracy and emissions-system compatibility.

Key Features

• Stainless steel body material for exhaust durability
• Federal / EPA direct-fit design
• 2-bolt welded inlet connection
• 2.30 in. OD outlet connection
• 1 O2 sensor port
• 27 in. overall length
• Includes inlet gasket and inlet hardware
• Built to OE dimensions for listed Mazda CX-5 applications

Detailed Description

AP Exhaust part number 644040 is a direct-fit catalytic converter for Mazda CX-5 models listed below. It is designed for center and rear exhaust positions depending on year and configuration, with fitment covering 2013-2023 Mazda CX-5 applications. The converter uses AP Exhaust’s Direct Fit Converter platform, which emphasizes OE-style dimensions and consistent fitment for emissions-system replacement work.

Manufacturer engineering for this line centers on advanced production methods and substrate chemistry that support efficient catalyst loading while keeping the converter built to exact OE dimensions. For repair shops and DIY installers working on a Mazda CX-5, 644040 provides a replacement path for emissions-related exhaust service without requiring custom fabrication on the listed applications.

This part cross-references PY35-20-55XA for the same application.

What It Helps Address

• Failed or restricted catalytic converter on a Mazda CX-5
• Check engine light concerns related to catalyst efficiency
• Exhaust flow loss caused by a deteriorated converter
• Emissions test failure tied to converter performance
• Replacement needs for OE-style welded exhaust assemblies

Installation Notes and Tips

• Fits 2022-2023 Mazda CX-5, center.
• Fits 2018-2021 Mazda CX-5, rear.
• Fits 2013-2017 Mazda CX-5, N/A; 78305 Resonator Pipe is required for installation. Federal and California emissions noted in the fitment data.
• Fits 2014-2017 Mazda CX-5, rear; OE is a welded assembly and 78305 pipe is required to complete installation.
• Verify emissions certification and state restrictions before installation, especially for California, Colorado, Maine, and New York listings noted by the manufacturer.
• Confirm O2 sensor port location and exhaust connection style against the vehicle before beginning work.

Quality Assurance

AP Exhaust states that the Direct Fit Converter line is manufactured with automated workstations, spinner welding equipment, and high-speed production lines to maintain OE dimensions and fitment consistency. The brand also notes a focus on efficient substrate loading and competitive pricing through its ARISTO substrate chemistry and manufacturing process.