Header Manifold for Toyota Pickup Truck 4Runner (1990-1995) 2.4L Engine

High-Flow Stainless Steel Header for 1990-1995 Toyota 4Runner & Pickup (22R-E/N120)

What It Does: Replaces the restrictive, crack-prone factory cast-iron exhaust manifold with a high-flow stainless steel header to improve exhaust scavenging and reduce engine backpressure.

The Stock 22R-E Exhaust Bottleneck

The factory exhaust manifold on the 1990-1995 Toyota 2.4L (22R-E) is a heavy cast-iron component designed for production speed rather than flow efficiency. Over decades of operation, these cast units are notorious for developing hairline fractures due to extreme thermal fatigue and heat-cycling. Internally, the OEM manifold features rough casting flash and sharp 90-degree bends that create significant turbulence. This turbulence creates a 'chokepoint' effect, trapping heat in the cylinder head and forcing the engine to work harder during the exhaust stroke, which ultimately reduces overall efficiency and throttle response.

The Engineering Solution

This header is engineered to rectify the 22R-E’s breathing limitations through the use of mandrel-bent tubing and high-grade polished stainless steel. Unlike standard crush-bending, mandrel bending maintains a constant 1.50" primary diameter throughout every curve, ensuring laminar exhaust flow and maximizing gas velocity. The CNC-machined flanges provide an ultra-flat mating surface that eliminates the common 'exhaust tick' leak found in warped stock manifolds. Constructed with a combination of TIG and MIG welding for structural integrity, this header features a 2.25" OD outlet to facilitate rapid gas evacuation, effectively lowering EGTs (Exhaust Gas Temperatures) and improving the volumetric efficiency of the engine.

Technical Specifications

Compatibility

• Toyota 4Runner (1990-1995) 2.4L 2WD Only
• Toyota Pickup (1990-1995) 2.4L 2WD Only
• Trim: 2.4L Engine Only
• Note: Fits 2WD models exclusively

The Toyota Durability Standard

The Toyota 22R-E is a legendary powerplant known for its bulletproof reliability. This header upgrade is built to match that caliber of engineering, offering the durability needed for heavy-duty towing and high-mileage utility. By replacing the brittle factory iron with high-quality stainless steel, you ensure your exhaust system can handle the rigors of daily work without the risk of manifold failure or power-robbing leaks.