HKS 14019-AM002 GT Extension Kit Twin Port SUS304 Downpipe with O2 Sensor Port

The HKS 14019-AM002 GT Extension Kit is a precision-engineered exhaust upgrade designed to maximize performance from the stock turbocharger. Constructed from SUS304 stainless steel, this twin-port extension kit replaces the restrictive factory O2 housing with a free-flowing unit and includes an integrated downpipe featuring an additional O2 sensor port.

Key Features:

• Twin-port design — utilizes separate main port (turbine exhaust) and bypass port (wastegate actuator) to reduce exhaust gas interference and improve flow efficiency
• SUS304 stainless steel construction — provides excellent heat resistance, corrosion resistance, and long-term durability
• CAD-designed lost wax cast extension elbow — complex geometry is manufactured without welds, eliminating the risk of heat-related cracking and ensuring a smooth internal surface for optimal exhaust gas flow
• Flexible joint connection — extension portion and front pipe are connected via a flexible joint to improve durability and reduce stress on the assembly
• Integrated front pipe and downpipe — combines extension pipe and front pipe into one complete system for maximum exhaust efficiency
• Additional O2 sensor port — accommodates wideband or secondary O2 sensors for tuning flexibility
• Main diameter: 62mm / Bypass diameter: 65mm

By improving exhaust efficiency at both low and high RPM, the GT Extension Kit helps boost pressure build earlier in the RPM range, delivering increased power and torque across the entire powerband. This kit is a foundational exhaust upgrade for any performance build targeting maximum output from the stock turbo platform.

Note: This product is not CARB certified and is not legal for sale or use in California or other states requiring CARB compliance. Intended for off-road or competition use only where applicable.