Catalytic Converter with Resonator and Muffler for Mitsubishi Lancer (2009-2011) 2.0L 2.4L

Direct-Fit Replacement Catalytic Converter with Resonator and Muffler for 2009-2011 Mitsubishi Lancer (CY4A/CY5A)

What it Does: The direct-fit catalytic converter with resonator and rear muffler replaces degraded emissions and silencing hardware on the 2009-2011 Mitsubishi Lancer to restore factory backpressure, eliminate exhaust leaks, and clear emissions fault codes.

The Stock Mitsubishi Lancer Exhaust Degradation

Factory exhaust assemblies on the CY4A and CY5A platforms suffer from structural corrosion along thin-wall mild steel tubing, especially at the underbody welded seams and rear flange interfaces. Road salt and repeated thermal expansion lead to flange rot, acoustic perforation, and internal ceramic washcoat sintering within the catalytic converter core. This breakdown results in catalyst efficiency diagnostic trouble codes (such as P0420), cabin exhaust intrusion, elevated cabin drone, and disrupted exhaust scavenging dynamics that degrade low-end engine torque.

The Engineering Solution

This comprehensive underbody assembly provides a complete, bolt-in exhaust restoration. Engineered with a corrosion-resistant stainless steel converter body housing a high-flow ceramic substrate, it ensures optimal catalyst light-off and reliable Federal EPA emissions compliance. Precision robotic TIG-welded 2-bolt solid flanges match OEM exhaust hang points without requiring cutting or sleeve welding. The integrated center resonator cancels resonant standing waves, while the direct-fit rear muffler restores factory sound attenuation and balanced exhaust flow for naturally aspirated 4B11 and 4B12 powertrains.

What's Included

• 1 Underbody Catalytic Converter with Integrated Resonator Assembly (89-inch overall length)
• 1 Rear Muffler Assembly
• Exhaust Clamps
• Inlet and Outlet Flange Gaskets
• Mounting Hardware

Technical Specifications

Compatibility

• 2009-2011 Mitsubishi Lancer 2.0L 4-Cylinder Naturally Aspirated (DE, ES)
• 2009-2011 Mitsubishi Lancer 2.4L 4-Cylinder Naturally Aspirated (GTS)

Frequently Asked Questions & Fitment Warnings

Does this fit the CY4A/CY5A Lancer?

Yes, this is a direct fit for the 2009-2011 Mitsubishi Lancer equipped with the naturally aspirated 4B11 and 4B12 engines. It does NOT fit turbocharged Lancer Ralliart or Lancer Evolution models, and is not legal for sale or use in California, Colorado, New York, or Maine.

Are existing O2 sensor bungs included on the assembly?

Yes, the assembly features two integrated O2 sensor ports that accept original-equipment oxygen sensors without wiring harness modification.

The Mitsubishi Caliber

Maintain proper Japanese sport sedan dynamics by matching factory acoustic isolation, zero-leak flange sealing, and compliant backpressure characteristics across the entire powerband.