Exhaust Header for Ford Expedition (1997-2002) 4.6L

High-Flow Stainless Exhaust Headers for 1997-2002 Ford Expedition

What it Does: The high-flow exhaust header kit replaces the crack-prone factory cast-iron exhaust manifolds on the 1997-2002 Expedition to optimize exhaust gas scavenging, reduce backpressure, and eliminate recurring exhaust leaks.

The Stock Ford Expedition Manifold Failure

The OEM log-style cast-iron manifolds on the UN93 platform housing the Modular 4.6L 2V Triton engine suffer from severe heat retention and uneven thermal expansion. Over heavy-duty towing cycles, thermal shock warps the factory casting, repeatedly shearing off the rear exhaust studs on the aluminum cylinder heads and blowing out manifold gaskets. Additionally, the restrictive 90-degree log entries induce exhaust gas reversion, spiking backpressure and choking volumetric efficiency.

The Engineering Solution

Constructed from mandrel-bent T-304 stainless steel, this shorty header system replaces restrictive log geometry with tuned, free-flowing primary runners that accelerate exhaust pulse velocity. Thick, surface-ground flanges maintain uniform clamping force across cylinder exhaust ports to prevent warped flanges and broken studs. Precision TIG welds resist fatigue under heavy engine vibration, significantly lowering backpressure and improving mid-range torque delivery under load.

Technical Specifications

Compatibility

• 1997-2002 Ford Expedition XLT 4.6L V8 (UN93)
• 1997-2002 Ford Expedition Eddie Bauer 4.6L V8 (UN93)

Frequently Asked Questions

Does this fit the UN93 Expedition?
Yes, this is a direct fit for the 1997-2002 Ford Expedition equipped with the Modular 4.6L V8 engine.

Do these shorty headers require an ECU tune or modifications to downstream oxygen sensors?
No, these headers bolt directly to OEM catalytic converter downpipes and retain factory sensor placement without triggering a check engine light.

The Ford Towing Durability Standard

Engineered to handle the high thermal loads of continuous hauling and steep grades, upgrading to heavy-gauge stainless steel prevents recurring manifold failures while restoring the engine's intended torque band.