P0491

AIR System Insufficient Flow Bank 1

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Increased emissions
Unstable engine operation at idle
Check Engine light comes on

Causes

Clogged air channels of the secondary air system
Secondary air system valve malfunction
Problems with the secondary air pump
Open or short circuit in wiring harness
Air pressure sensor malfunction

How to Fix

Check the condition of the air channels of the secondary air system
Check the operation of the secondary air system valve
Check the secondary air system pump
Check wiring harness for damage
Check air pressure sensor

Related codes

P0492 P0410 P0411