P0491Powertrain (P)generic
Secondary Air Injection System Insufficient Flow Bank 1
The secondary air injection system on the engine's left side (Bank 1) is not pumping enough air into the exhaust to properly reduce emissions. This system helps burn unburned fuel in the exhaust, and insufficient flow means emissions will be high. The check engine light will illuminate.
No detailed repair guide linked yet. Check back soon or search for related issues.
