Catalytic Converter for Ford Expedition (1997-1998) 4.6L Left

Direct-Fit Left Catalytic Converter for 1997-1998 Ford Expedition (UN93)

What it Does: The Left Catalytic Converter replaces the degraded factory driver-side emissions assembly on the 1997-1998 Ford Expedition to restore correct exhaust backpressure, resolve catalyst efficiency check engine lights, and maintain EPA-compliant exhaust flow.

The Stock Ford Expedition Exhaust Degradation

With decades of thermal expansion and prolonged duty cycles, factory ceramic substrates on the UN93 platform break down, erode, or suffer from internal carbon glazing. On the Modular 4.6L V8, a restricted driver-side converter creates asymmetric exhaust bank backpressure, elevated exhaust gas temperatures (EGTs), and persistent OBD-II catalyst monitoring trouble codes (such as P0420). Left unchecked, high backpressure chokes cylinder scavenging and robs low-end towing torque.

The Engineering Solution

This direct-replacement left-bank assembly is manufactured with heavy-duty aluminized steel piping engineered to withstand road-salt corrosion and high thermal loads. Built to mirror factory routing, it features accurate factory-located oxygen sensor bungs, mandrel-formed transitions, and thick mounting flanges that seal flat against OEM manifolds without requiring cutting or custom welding. Inside, an advanced washcoat core provides high precious metal loading to convert carbon monoxide, hydrocarbons, and nitrogen oxides back to compliant baseline levels.

Technical Specifications

Compatibility

• 1997-1998 Ford Expedition 4.6L V8 4WD Only (Driver Side)
• Does not fit 2WD configurations
• Does not fit 5.4L V8 engines
• Does not fit XLT Plus packages
• EPA 46-State Legal (Not CARB compliant; cannot ship to CA, NY, CO, or ME)

Frequently Asked Questions

Does this fit the UN93 Expedition?

Yes, this is a direct fit for the 1997-1998 Ford Expedition equipped with the Modular 4.6L V8 engine and 4WD driveline.

Will this unit resolve catalyst efficiency check engine lights?

Provided downstream O2 sensors and engine fuel trims are operating within factory tolerances, this EPA-compliant converter will clear P0420 catalyst efficiency DTCs.

The Ford Truck Durability Standard

Designed for full-size sport utility platforms enduring heavy tongue loads and severe 4x4 operating conditions, this unit ensures your exhaust system withstands continuous towing strain while maintaining factory emissions integrity.