P0411 Obd2 Code: Secondary Air Injection Incorrect Flow

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P0411 Obd2 Code
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If your vehicle is diagnosed with the P0411 code, it has some problems with secondary injection. This code indicates that there may be an issue with airflow in the secondary air system. A defective secondary air injection will result in problems with the air-to-fuel ratio in the internal combustion engine. It is possible that this ratio is too low and that your engine will have difficulty producing speed whenever you press the gas pedal.

So, if your vehicle is having a problem with airflow in the secondary air system, we are at your disposal to help you fix it.

What is the P0411 OBD2 Code?

What is the P0411 OBD2 Code?By supplying fresh air into the exhaust system, the secondary air injection system helps to lower exhaust pollutants. The secondary air injection system incorporates critical components such as the check valve, which is placed at the air supply line’s inlet, and the cutoff valve, controlled either electrically or by vacuum.

The check valve’s primary function is to prevent exhaust gas from re-entering the system through to the pump, whereas the cutoff valve’s primary function is to control the amount of air that flows through the system.

Suppose there is a malfunction in these valves. In that case, it is indicated by the code P0411 that the ECU has determined that flow from the secondary air injection system is out of specification. The Check Engine Light is activated and shown on the dashboard due to this action. The light will be on until the system returns to normal operation or repairs are completed.

Symptoms of P0411 Code

The symptoms associated with the diagnostic trouble code P0411 may impair the vehicle’s ability to drive in certain situations. In contrast, similar symptoms may not harm the vehicle’s ability to operate in other cases.

On the other hand, there are also occasions where the sole symptom recorded is the lighting of the check engine light, with no additional symptoms present. Regardless of the consequences for driving ability, some of the most common symptoms of P0411 are as follows: (P0422 Obd2 Code)

  • The check engine light has been illuminated.
  • Fuel usage is high.
  • When under heavy acceleration, the engine backfires.
  • Poor acceleration and jerky running are common problems.
  • Squealing belts turned by a drive belt.

Causes of P0411 Code

An array of failures in the vehicle’s emission control system may result in a P0411 code. The most common causes associated with this code are as follows:

  • The air injection pump has failed due to mechanical failure.
  • A faulty air pump circuit or an errant air pump clutch.
  • Air control solenoids or airlines that are not functioning properly.
  • An excessive amount of carbon has accumulated in the air injection system.
  • Exhaust components with a spout or perforations.
  • Check the valve that has been damaged.
  • The injection system’s wiring harness was found to be faulty.

How can you Diagnose the P0411 OBD2 Code?

For diagnosing your vehicle for the P0411 OBD2 error code, the following are the pointers to consider: 

  • You can begin by scanning the vehicle’s ECU with a scan tool connected to the vehicle’s DLC port to see whether any codes have been stored in the ECU. There may be passed, present, or pending codes, each with its freeze frame data to consider.
  • Codes will be documented, freeze frame data will be noted, and everything will be cleared.
  • The technician will put the car through its paces to see if it can reproduce any symptoms.
  • Following this, a visual assessment of the air injection system will be carried out to identify any damaged hoses, excessive carbon, or damaged components.
  • Finally, the air pump operation will be monitored with the use of an advanced scan tool.

How to Fix P0411 OBD2 Code?

How to Fix P0411 OBD2 Code?

There is no one solution for the P0411 code, just as there is no single solution for virtually all other OBD-II codes. It is why most people would instead leave the job to a qualified automotive professional.

However, suppose you have the requisite automotive DIY abilities. In that case, you should be able to complete the job on your own—as long as you correctly diagnose the underlying problem, of course.

There are various options for repairing a P0411 error code, including cleaning the secondary air channels, a typical fix on GMC Terrain trucks. Determine the correct resolution by examining some fixes that other people have used to address a P0411 on their vehicle before proceeding.

As with any do-it-yourself repair, we recommend that you take advantage of all of the auto repair information and guidelines that are available online to assist you in determining the correct steps to take to resolve the P0041 code.

Following are the possible fixes for the P0411 error code:

  • Replacement of the air pump
  • Removal of carbon buildup in the secondary air system
  • Replacement of the vacuum hose
  • Replacement of the air solenoid
  • Wiring harness problems that need to be repaired or replaced


Can you drive with a bad secondary air injection?

While passing a smog test is a significant concern in and of itself, the actual danger from a faulty air pump is the likelihood that lower engine efficiency and drivability could result in a dangerous situation for you and your passengers’ safety while driving.

How do I know if my secondary air pump is working?

The secondary air pump must begin operating audibly after the engine has been started from a cold start. First, start the engine of the car. Suppose the secondary air pump’s power supply is satisfactory, but the secondary air pump operates with a scraping, whistling, or scratching noise or does not operate at all. In that case, the secondary air pump should be replaced.


Diagnosing P0411 is relatively simple in theory, but it may be more difficult in practice due to the technical nature of the problem. Consequently, if you ever have issues diagnosing this code, follow the above techniques to solve it. And, if you are having problems doing it yourself, it is better to get the assistance of a professional to look into it.