Catalytic Converter for Ford F-150 (2005-2008) 4.2L Left & Right

Direct-Fit Left and Right Catalytic Converter Set for 2005-2008 Ford F-150 (P221)

What it Does: The direct-fit left and right catalytic converter set replaces deteriorated or clogged factory emissions units on the 2005-2008 Ford F-150 4.2L to clear catalyst efficiency DTCs (P0420/P0430) and restore exhaust gas velocity.

The Stock Ford F-150 Catalytic Converter Degradation

High-mileage P221 chassis work trucks running the 4.2L Essex V6 frequently suffer from washcoat erosion, internal ceramic substrate thermal breakdown, and carbon poisoning. Unburned hydrocarbons and thermal cycling cause factory washcoats to degrade or melt, inducing severe exhaust backpressure that chokes volumetric efficiency and triggers downstream oxygen sensor threshold diagnostic codes.

The Engineering Solution

Engineered for the Ford Essex 4.2L powertrain, this bank 1 and bank 2 replacement assembly uses mandrel-bent 409 stainless steel tubing coupled to high-flow ceramic substrates loaded with noble metal washcoats for Federal EPA compliance. The driver-side assembly (OEM 16786) features a 12-inch round canister with a 3.25-inch ID spherical flare 2-bolt flange running to a 2.5-inch OD outlet across a 37-inch span. The passenger-side assembly (OEM 16787) utilizes a 6.5-inch x 9-inch x 12-inch oval casing with dual 3.25-inch ID inlets and a 2.5-inch OD collector over a 48.25-inch span, ensuring factory hanger alignment and leak-free flanged sealing without custom fabrication.

What's Included

• 1 Left-Side Direct-Fit Catalytic Converter (Part # 16786)
• 1 Right-Side Direct-Fit Catalytic Converter (Part # 16787)
• Installation Hardware and Flange Accessories

Technical Specifications

Compatibility

• 2005 Ford F-150 4.2L V6 (Standard Cab, Extended Cab)
• 2006 Ford F-150 4.2L V6 (Standard Cab, Extended Cab)
• 2007 Ford F-150 4.2L V6 (Standard Cab, Extended Cab)
• 2008 Ford F-150 4.2L V6 (Standard Cab, Extended Cab)

Frequently Asked Questions & Fitment Warnings

Does this fit the P221 F-150?

Yes, this is a direct fit for the 2005-2008 Ford F-150 equipped with the 4.2L Essex V6 engine; it does not fit 4.6L or 5.4L Triton V8 models.

Is this catalytic converter legal for sale or use nationwide?

This Federal EPA-compliant set is not CARB-certified and is not legal for sale, installation, or registration on vehicles registered in California, Colorado, New York, or Maine.

The Ford Heavy-Duty Standard

Built to withstand severe heat cycles and vibration under heavy payload and towing duty, these converters maintain uncompromised flow characteristics and structural integrity over severe work-cycle demands.