1999-2004 Discovery II Secondary Air Injection Valve

Maintain emissions system efficiency with this Secondary Air Injection Valve for the 1999–2004 Land Rover Discovery II. Designed to support both left and right side configurations, this OEM-spec valve (Part # WAV100380) plays a critical role in the secondary air system, which reduces cold-start emissions by injecting air into the exhaust stream.

The secondary air system introduces fresh air into the exhaust to promote cleaner emissions during engine warm-up. A failing valve can cause poor emissions performance, engine fault codes, or failed inspections. This direct-fit valve restores proper function, helping your Discovery II meet emissions standards while supporting smooth engine operation.

Key Features:

• Fits 1999–2004 Land Rover Discovery II
• Land Rover Part Number: WAV100380
• Works on both left and right sides of the engine
• Essential for proper secondary air system function
• Supports reduced emissions during cold starts
• OEM-style fit and design for reliable performance
• Helps prevent CEL (check engine light) related to emissions
• Durable construction to withstand high-heat exhaust environments

What is Secondary Air? Secondary air systems inject oxygen into the exhaust during cold starts to help burn off excess hydrocarbons and reduce emissions. The valve regulates airflow into the exhaust manifold, improving combustion efficiency until the catalytic converter reaches operating temperature.