StopOrDrive

Enter a 5-character code such as P0420, P0301, or P0457.

We don't have that code yet

Codes starting with P are engine and transmission, B are body, C are chassis, and U are network communication. A 0 as the second character means a generic code shared by all makes; a 1 means a manufacturer-specific code, so its meaning depends on your brand.

A steady check engine light usually means get it checked soon. A flashing check engine light means an active misfire: reduce speed and stop driving as soon as it is safe.

That doesn't look like an OBD-II code

A valid code is one letter (P, B, C, or U) followed by four characters, for example P0420.

P0411 Secondary air injection system incorrect flow

Can I drive with P0411?

Drive

Safe to keep driving normally. Fix it when convenient.

Only affects emissions during cold starts. The engine runs normally.

What does P0411 mean?

The air pump system that helps the catalytic converter warm up after a cold start is not moving the expected amount of air.

What causes P0411?

  1. Failed air pump
  2. Stuck air check valve
  3. Leaking or disconnected hoses
  4. Blown fuse or failed relay

How much does it cost to fix P0411?

$150 – $1,000

Check valve: $150–$350. Air pump: $400–$1,000.

Confirm the code yourself

A low-cost scanner lets you read the code, clear it, and see if it comes back before paying for a diagnosis.

Check current price on Amazon. We may earn a commission if you buy through these links. As an Amazon Associate I earn from qualifying purchases.