Exhaust Header for Scion xA xB (2004-2006)

High-Flow Stainless Exhaust Header for 2004-2006 Scion xA, xB

What it Does: The Exhaust Header replaces the restrictive factory cast manifold on 2004-2006 Scion xA and xB models to reduce exhaust backpressure, optimize pulse scavenging, and accelerate exhaust gas velocity.

The Stock Scion xA, xB Manifold Restriction

The OEM cast iron exhaust manifold on the 1.5L 1NZ-FE platform is engineered for low-cost production rather than gas flow efficiency. Its short, unequal-length runners feature rough internal casting flash and abrupt merge angles that create high backpressure against the exhaust valves. This restriction impedes complete cylinder evacuation during overlap, causing localized thermal soak near the cylinder head and choking upper-RPM efficiency on both the XP30 and XP60 chassis.

The Engineering Solution

This direct-replacement performance manifold utilizes mandrel-bent stainless steel primary runners designed to maintain constant cross-sectional area throughout every bend. Precision-welded joints and thick, warp-resistant mounting flanges ensure a leak-free seal against the cylinder head under extreme heat cycling. By pairing smooth internal transitions with a low-turbulence collector, this header improves scavenging dynamics, reduces thermal retention in the engine bay, and includes pre-located O2 sensor bungs for straightforward installation.

Technical Specifications

Compatibility

• 2004-2006 Scion xA 1.5L Hatchback (NCP61)
• 2004-2006 Scion xB 1.5L Wagon (NCP31)

Frequently Asked Questions

Does this fit the XP30 and XP60 xA, xB?
Yes, this is a direct bolt-on fit for all 2004-2006 Scion xA and xB applications running the transverse 1NZ-FE 1.5L engine.

Do I need to weld or modify the stock exhaust piping during installation?
No cutting or welding is required; this header matches standard downpipe flange locations and retains factory O2 sensor bung thread pitch.

The Scion Tuner Standard

Built for the high-revving demands of lightweight compact platforms, this header provides the flow capacity and mechanical resonance essential for unlocking genuine naturally aspirated performance and a crisp, aggressive exhaust tone from your 1.5L powertrain.