Dorman 911-646 Secondary Air Injection Check Valve

Reliable Secondary Air Injection Check Valve for Lexus and Toyota

The Dorman 911-646 Secondary Air Injection Check Valve is engineered to maintain optimal emission control in select Lexus and Toyota models. Crafted from durable cast aluminum with a diaphragm valve design, this component ensures consistent performance under varying conditions.

• Constructed from cast aluminum for strength and corrosion resistance
• Black and silver finish for durability and visual inspection
• Inlet size: 0.4 inches; outlet size: 0.47 inches for precise fitment
• Maximum pressure rating of 50 psi to handle emission system demands
• Operates effectively within a temperature range of -40°C to 125°C
• Includes one secondary air injection check valve, hardware, and gaskets for installation

Durable Design and Precise Fitment for Emission Control Systems

The Dorman 911-646 check valve is designed specifically for the secondary air injection system, which helps reduce harmful emissions during engine startup. Its diaphragm valve type provides reliable one-way airflow, preventing exhaust gases from flowing back into the air injection system. The cast aluminum construction offers resistance to heat and corrosion, essential for the demanding environment under the hood. The valve’s inlet and outlet sizes (0.4 in and 0.47 in respectively) ensure compatibility with the air injection lines on Lexus and Toyota vehicles such as the 4Runner, GX470, Land Cruiser, LX470, Sequoia, and Tundra.

Compatible Lexus and Toyota Models

This secondary air injection check valve is compatible with the following vehicles:

• Lexus GX470
• Lexus LX470
• Toyota 4Runner
• Toyota Land Cruiser
• Toyota Sequoia
• Toyota Tundra

Common Issues Addressed by the Dorman 911-646 Check Valve

• Prevents backflow of exhaust gases into the air injection system
• Helps maintain proper secondary air injection system pressure
• Reduces risk of emission control system failure codes
• Improves cold start emission performance
• Prevents damage to air injection pump and related components

Installation Notes and Tips

• Ensure the engine is cool before installation to avoid injury
• Use the included hardware and gaskets for a secure, leak-free fit
• Verify inlet and outlet hose sizes match the valve specifications (0.4 in inlet, 0.47 in outlet)
• Inspect surrounding components for wear or damage during replacement
• Follow vehicle-specific service manual instructions for removal and installation

Quality Assurance and Warranty Information

Dorman manufactures the 911-646 Secondary Air Injection Check Valve to meet or exceed OEM standards for fit, form, and function. The cast aluminum material and diaphragm valve design provide durability and reliable operation within the specified temperature and pressure ranges. This part is backed by Dorman’s limited warranty, ensuring coverage against defects in material and workmanship under normal use.