The Lemon IndexThe secondary air system isn't moving enough air on bank 1.
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
Failed air pump. Then: stuck valve; clogged passage.
Owners named P0491 in 6 complaints to the U.S. government, most often on the Volkswagen.
The details
What P0491 means
The secondary air system isn't moving enough air on bank 1.
Can I drive with P0491?
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
Common causes of P0491
- Failed air pump
- Stuck valve
- Clogged passage
A shop should confirm the cause with a scan and tests before replacing parts.
Related codes
P0496 P0464 P0463 P0462 P0461 P0460 P0457 P0456
Quick answers
What does P0491 mean?
Secondary Air Injection System Insufficient Flow (Bank 1). The secondary air system isn't moving enough air on bank 1.
Can I drive with P0491?
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
What causes P0491?
Failed air pump; Stuck valve; Clogged passage.
Counts: NHTSA owner complaints whose text names P0491. A complaint is an owner's report, not a diagnosis. Meanings: the standard SAE J2012 definitions in our own words; manufacturer codes only where verified for that make. General information, not repair advice for your car.