p0491
Moderate
Porsche · Sedans & Sports Cars
Secondary Air Insufficient Bank 1
Quick Answer
Error code P0491 on your Porsche Sedans & Sports Cars means: Secondary Air Insufficient Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Inspect secondary air hoses for blockage or damage
2
Check secondary air check valve for proper operation
3
Test secondary air pump motor with power directly applied
4
Verify air pump electrical connector and wiring integrity
5
Check engine control module for air pump command signal
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Secondary air injection pump
Secondary air hoses
Air check valve
Air pump relay
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