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P0411MinorEmissions

P0411: How to Diagnose & Fix — Secondary Air Injection System Incorrect Flow Detected

5 vehicles · 4 makes · $80-$4,000 repair

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How to diagnose and fix P0411: most-reported vehicles

Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.

Toyota Tundra · 2005–2013

Community reported
8,500 owners
Link to this issueError Codes:P0410P0411P0412P0418P2440P2443P2445P2447P0419

The secondary air injection pump is prone to failure due to water intrusion. The electric motor is located in the wheel well with moisture exposure, and the rubber boot covering the motor traps water, causing the pump to short circuit. This triggers check engine lights with codes P2440, P2443, P2445, P2447, P0418, or P0419. Some vehicles may enter limp mode.

Common Symptoms

  • Check engine light illumination
  • Jet engine noise on cold startup
  • Decreased fuel economy
  • Limp mode activation
  • Rough idle when cold

How to Fix

Toyota issued a service bulletin for 2007-2010 models covering replacement of the entire air injection system. Repair costs range from $2,000-$4,000 for OEM replacement. Some owners opt for aftermarket bypass kits with block-off plates.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Toyota 17610-0S010 genuine secondary-air pump assembly

    replace the corresponding pump only when active testing and the applicable Toyota program identify it as failed Fitment/availability: Cataloged for selected 2007-2013 Tundra applications; exact engine, side/quantity, DTC branch, VIN and …

    ToyotaPartsNow
  • Toyota 17610-0S030 genuine secondary-air pump assembly

    replace the program-matched pump after active-test confirmation, with all required valves, inlets, gaskets and calibration handled separately Fitment/availability: Cataloged for selected 2012-2021 4.6L/5.7L applications; on this card use…

    ToyotaPartsNow

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Owner tips & cautions

  • TipDIY repairs can save significantly - dealer charges $2,000-$4,000 but DIY costs are typically 50-70% less
  • TipConsider OEM parts for critical components like sensors and electrical parts - aftermarket can be unreliable
  • TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
Typical repair cost:$1,500 - $4,000

Research This Issue

Based on 8,500 owner reports

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Community Reported
High Confidence8,500 owner reportsLast reported by owners Feb 2024Reviewed Feb 2026

Toyota Sequoia · 2001–2009

Community reported
2,400 owners
Link to this issueError Codes:P0410P0411P0412P0418P2440P2442

The 4.7L 2UZ-FE's secondary air injection system fails due to corroded air switching valves (ASVs) and seized air pumps. Moisture enters the system and corrodes internal components. Causes check engine light with P2440/P2442 codes.

Common Symptoms

  • Check engine light with P2440 or P2442 codes
  • Rough idle on cold start
  • Ticking or buzzing noise from air pump on startup
  • Failed emissions testing

How to Fix

Replace air switching valves (Toyota 25701-50040 and 25702-50011) and air injection pump (Toyota 17610-0S010) if seized. Many owners bypass the system entirely with block-off plates since it only operates during cold start for emissions. Bypass plates available from Trail Gear or fabricated from aluminum.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Toyota 17600-0F010 secondary air injection pump assembly

    replace a debris-damaged secondary-air pump after bulletin diagnosis Fitment/availability: Exact pump listed by T-SB-0230-12 Rev1 for an eligible 2005-2007 Sequoia 2UZ-FE; replace only when bulletin inspection finds debris in the pump Fi…

    ToyotaPartsDeal
  • Toyota 25710-50022 air switching valve assembly

    replace the corresponding failed or debris-damaged air switching valve Fitment/availability: Exact air switching valve assembly listed by T-SB-0230-12 Rev1; use only on the diagnosed valve branch and confirm VIN before ordering Fitment/a…

    AutoPartsPrime
  • Toyota 25720-50011 electric air control valve No. 1

    1 valve only when its bulletin diagnostic branch confirms failure or damage Fitment/availability: Exact No. 1 valve listed by T-SB-0230-12 Rev1; not interchangeable with the No.

    ToyotaPartsDeal
  • Toyota 25720-50020 electric air control valve No. 2

    2 valve only when its bulletin diagnostic branch confirms failure or damage Fitment/availability: Exact No. 2 valve listed by T-SB-0230-12 Rev1; not interchangeable with the No.

    ToyotaPartsDeal
  • Toyota 89580-34012 air injection control driver

    replace the air-injection control driver on the bulletin's residual-code branch Fitment/availability: Exact driver identified by T-SB-0230-12 Rev1; use only if P0418 or P2445 remains after the applicable mechanical repair and confirmatio…

    ToyotaPartsDeal
  • Toyota 17171-50030 intake manifold-to-head gasket No. 1

    reseal both intake-manifold-to-head joints during the applicable repair Fitment/availability: Exact gasket listed by T-SB-0230-12 Rev1; bulletin quantity is two when the applicable air-injection repair requires intake-manifold removal Fi…

    ToyotaPartsDeal
  • Toyota 17377-50010 air tube gasket No. 4

    replace disturbed air-tube seals during the bulletin repair Fitment/availability: Exact air-tube gasket listed by T-SB-0230-12 Rev1; bulletin quantity is four for the applicable repair Fitment/availability: Ships in 1-3 business days wit…

    ToyotaPartsDeal

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$100 - $2,000

Research This Issue

Based on 2,400 owner reports

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Community Reported
High Confidence2,400 owner reportsLast reported by owners Feb 2026Reviewed Feb 2026

Toyota Sequoia · 2008–2019

Community reported
1,100 owners
Link to this issueError Codes:P0410P0411P0412P0418P2440P2441P2442P2443P2444P2445

2nd-gen Sequoias with the 5.7L 3UR-FE also suffer from secondary air injection pump failures, similar to the 1st gen but with updated part numbers. The pump seizes from internal moisture corrosion, triggering P2440-P2445 codes and check engine light.

Common Symptoms

  • Check engine light with P2440-P2445 codes
  • Loud buzzing or grinding on cold start
  • Air pump not engaging on startup
  • Failed emissions test

How to Fix

Replace secondary air injection pump (Toyota 17610-0S010 or Dorman 306-058). Replace air switching valves if corroded. Aftermarket pumps are available at lower cost. Some owners install check valves in the air line to prevent moisture backflow into the pump.

Typical repair cost:$300 - $1,500

Research This Issue

Based on 1,100 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High Confidence1,100 owner reportsLast reported by owners Feb 2026Reviewed Feb 2026

Audi A8 · 1997–2003

Link to this issueError Codes:P0410P0411P0491P0492

The 4.2 V8 in the D2 A8 (both the early 32-valve ABZ and the later 40-valve AKB/AUX/AYS/BFM) runs a vacuum-operated secondary air injection system with one combi valve per cylinder head, fed by small-diameter hard plastic vacuum lines that become brittle with heat and crack. Both banks have their own combi valve, and it is usually the hard vacuum line that goes to them that breaks and causes a vacuum leak and inoperable SAI. Owners report replacing vacuum hoses and the SAI relay only to have the CEL return, and then having to look at replacing the SAI pump (SAIP), the solenoid on top of the engine, and replacing/cleaning out the combi valves aft of each cylinder head, which involves carbon buildup in the cylinder head ports. Symptom is a check-engine light shortly after a cold start with P0410 (or banked variants P0491/P0492).

Common Symptoms

  • Check engine light after cold start
  • Audible hissing from engine bay at cold start
  • Rough idle for first 30-90 seconds after cold start
  • Failed emissions/smog test
  • Pump noise (whining) on cold start

How to Fix

Diagnose by starting the engine cold so the SAI system runs and listening for the vacuum leak, then looking around for the crack. Sticky/partly opening combi-valve or slow running pump are all candidates — you can spin the pumps up using VCDS output tests to verify pump current draw. Replace brittle vacuum hose with silicone, test combi valves with a hand vacuum pump (they should hold vacuum and audibly click open), and if codes persist with new vacuum/valves the SAI ports in the head will need to be carbon-cleaned. The pump itself (smog pump) typically fails when a leaking combi valve allows exhaust moisture to back-feed and corrode the impeller.

Typical repair cost:$80 - $1,400
Sources for this issue (1)
  • Audi TSB 2033001/12 - Later 2010-2012 A8 4.2 FSI Secondary-Air Restriction Diagnosistsb

Research This Issue

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Community Reported
High ConfidenceLast reported by owners May 2026Reviewed May 2026

Volkswagen Jetta · 2005–2014

Link to this issueError Codes:P0411P0410P0491P2440

The 2.5L five-cylinder Jetta (Mk5 2005-2010 and Mk6 2011-2014, engine codes BGP/BGQ/CBTA/CBUA) very commonly fails its secondary air injection system, which pumps air into the exhaust on cold start to light off the catalyst faster. The root cause is almost never the pump itself: the one-way combination valve (combi valve) between the pump and the exhaust fails and lets hot, moist exhaust gas back into the pump. That moisture corrodes the pump internals and, in winter, freezes - which is why many failures announce themselves on the first hard freeze, often blowing the pump fuse or burning out the J299 relay. The signature is a loud jet-engine or shop-vac roar for 60-90 seconds after a cold start, followed by a check engine light. The system only runs on cold start, so the car otherwise drives normally, but it is an emissions-test failure.

Common Symptoms

  • Loud jet-engine or vacuum-cleaner noise for about a minute after cold start
  • Check engine light with secondary air injection codes
  • Emissions test failure with readiness monitors incomplete
  • Blown secondary air pump fuse, particularly in freezing weather
  • Rough or elevated idle for the first minute after a cold start

How to Fix

Diagnose properly before parts-swapping: check the J299 secondary air pump relay and its fuse, inspect the rubber hoses between pump and combi valve for cracks, and test the combi valve for leak-back. The critical rule owners repeat is that the combi valve MUST be replaced whenever the pump is replaced - fitting a new (or used) pump behind an old combi valve simply destroys the new pump. Expect pump plus combi valve plus hoses. No recall exists; this is a customer-pay repair once out of the federal emissions warranty (8 years/80,000 miles on emissions-related components may cover some cars).

Typical repair cost:$450 - $1,100
Sources for this issue (3)
  • PLEASE NEED HELP WITH Secondary Air Injection pump - Volkswagen Jetta Junkiesforum
  • VW 2.5 Secondary Air Injection Incorrect Flow (P0411) - ShopDAParticle
  • Troubleshooting P0411 code on a Jetta 2.5article

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Aug 2026

Find P0411 by make

Browse every documented model and issue for your make.

Audi · 1 issueSubaru · 1 issueToyota · 3 issuesVolkswagen · 1 issue

P0411 code reference

General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.

Frequently asked questions

What does P0411 mean?

P0411 stands for "Secondary Air Injection System Incorrect Flow Detected." This emissions code means the secondary air injection system is flowing an incorrect amount of air. That system pumps fresh air into the exhaust shortly after a cold start to help the catalytic converter heat up and burn off pollutants faster. The computer monitors the resulting change in exhaust oxygen readings, and sets this code when the measured airflow is too high, too low, or otherwise not what it commanded. It is primarily an emissions issue and often traces to the air pump, valves, or their plumbing.

What are the most common causes of P0411?

The most common causes of P0411 are: Failed secondary air injection pump, Stuck or faulty air switching/check valve, Carbon or moisture clogging the air passages, Leaking, cracked, or disconnected air hoses, Faulty pump relay or electrical wiring, Damaged or corroded connectors, Faulty vacuum control solenoid for the system. The specific cause varies by vehicle.

How much does it cost to fix P0411?

Repair costs for P0411 range from $80 to $4,000, depending on the vehicle and root cause.

Which vehicles are affected by P0411?

Au7o has documented P0411 across 5 vehicle models from 4 manufacturers: Audi, Subaru, Toyota, Volkswagen.

Related codes

  • P0410 · Secondary Air Injection System Malfunction
  • P0412 · Secondary Air Injection System Switching Valve A Circuit
  • P0413 · Secondary Air Injection System Switching Valve "A" Circuit Open
  • P0414 · Secondary Air Injection System Switching Valve "A" Circuit Shorted
  • 01447 · EVAP System (VAG)
  • P0030 · HO2S Heater Control Circuit (Bank 1 Sensor 1)
  • P0031 · HO2S Heater Control Circuit Low (Bank 1 Sensor 1)
  • P0037 · HO2S Heater Control Circuit Low (Bank 1 Sensor 2)
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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