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P0411: Secondary Air Injection System Incorrect Flow Detected

What it means

The secondary air system is flowing the wrong amount of air.

Severity: Low Cold-start emissions only.

Common causes

  1. Failing air pump
  2. Stuck check valve
  3. Blocked air passages
  4. Leaking hoses

Most common causes first. Exact causes vary by make, model and engine.

Can I fix it myself?

Sometimes DIY. Water-damaged check valves are common; inspect hoses.

Repair cost

SEEDED ESTIMATE Roughly $310–$1250

Most likely repair: secondary air pump. Diagnosis fees, taxes and other causes are not included.

LineLowHighBasis
Secondary air pump$208$853Typical listed retail range, source
Labor 1–2.5 hr$100$400$100–$160/hr, shop survey

⚠️ This is an editorial placeholder range for this type of repair. It is not based on real invoices or licensed pricing data yet. Real ranges will appear here once enough reader invoices for P0411 are verified.

Verified reader invoices for P0411: 0. Share your repair bill to help build real costs.

Tools that can read P0411

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Related codes

P0400 · P0401 · P0402 · P0403 · P0404 · P0410

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