P0491 trouble code Chrysler? (Best solution)

Error Code P0491 is defined as Secondary Air Injection System Insufficient Flow Bank 1. This means there’s a problem on the side on the engine that holds the cylinder #1, usually caused by a bad air inlet, relay, fuse, pump or faulty wires.


  • Trouble code P0491 trouble code Chrysler is defined as Secondary Air Injection Excess/Insufficient Air Flow. Obviously the P0491 trouble code is related to a problem with the secondary air injection system. To understand the purpose of the secondary air system and to understand how it works, read this post

How do I fix code P0491?

What repairs can fix the P0491 code?

  1. Replacing any damaged wiring, connectors, or other electrical components.
  2. Replacing the secondary air injection pump.
  3. Replacing the pump’s one-way check valve.
  4. Repairing or replacing any damaged vacuum hoses or fittings which could be causing a vacuum leak.
  5. Replacing pump fuses.

What does code P0491 mean?

Diagnostic trouble code (DTC) P0491 stands for “ Secondary Air Injection Insufficient Flow Bank 1.” It is logged once the vehicle’s powertrain control module (PCM) perceives that there is a possible issue within the SAI system. This system is also commonly called AIR, which means air-injection reaction.

What is code P0410?

Code P0410 is the result of the Engine Control Module (ECM) indicating a malfunctioning Secondary Air Injection System. This happens when the O2 sensor does not accurately detect the changes in the O2 level of the exhaust while the air injection system is functioning.

What is code P2440 mean?

The P2440 diagnostic trouble code is an indication that the Powertrain Control Module (PCM) has detected that the switching valve of the secondary air injection system is stuck open on Bank 2.

How do I fix error code P0410?

What repairs can fix the P0410 code?

  1. Replacing the air injection pump and power relay.
  2. Replacing O2 sensors that respond too slow as they age.
  3. Replacing the air injection pump intake filter clogged with debris.

How do I fix code P0410?

To get rid of this error code, you can do the following:

  1. Replace both the air pumps and the one-way check valve.
  2. Try and clean the air pump and test it. The one-way air check valve must be replaced as well.
  3. Replace the inlet hose of the air pump.
  4. Replace the fuse of the air pump (you can find it under the hood)

Can I drive my car with a P0410 code?

You may drive your vehicle with a P0410 however keep in mind your vehicle will not pass a smog inspection. Problems with the air injection system will not cause any driveability symptoms. The check engine light or malfunction indicator lamp will be illuminated as long as a P0410 is recorded in the ECC.

What causes P2440?

Error Code P2440 is defined as Secondary Air Injection System Switching Valve Stuck Open Bank 1. This indicates a stuck open problem in the switching valve of the secondary air injection system in Bank 1.

What would be a concern if the SAI one way check valve was stuck open?

If a P2442 code comes up, a one-way check valve is stuck open in the secondary air injection system, causing too much airflow into the exhaust and allowing hot exhaust gas to travel back into the pump. If the PCM receives a voltage reading of more than 10% of the allowed amount the P2442 code will be stored.

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

5 Symptoms of a Bad Secondary Air Injection Pump

  1. 1) Check Engine Light.
  2. 2) Failed Emissions Test.
  3. 3) Weak Acceleration.
  4. 4) Engine Stalling.
  5. 5) Low Idle.

P0491 trouble code Chrysler

Code for troubleshooting It is classified as Secondary Air Injection Excess/Insufficient Air Flow in the P0491 fault code from Chrysler. The P0491 issue code indicates that there is a problem with the secondary air injection system, which is not surprising. This page will help you understand the function of the secondary air system as well
as how it operates.

Most likely cause of a P0491 trouble code

This trouble code can be caused by a faulty pump, a faulty check valve, a restriction in the tubing between the secondary air pump and the exhaust manifold, or a restriction inthe exhaust manifold itself. The P0491- Secondary Air Injection–Excess/Insufficient Air Flow trouble code is displayed when the secondary air pump is faulty. During cold starting, the system makes use of the oxygen sensor to determine whether or not the system is running low on oxygen. In response to the engine temperature and the MAF sensor data, the computer determines the correct air/fuel combination.

A test can be performed by the PCM by abruptly turning on and off the pump to check what results are returned by the oxygen sensor, depending on the vehicle’s make, model, and engine.

A low flow code will be generated if there is any limitation in the flow to this chamber.

Check the secondary air ports

If the port is blocked, the additional air will not be detected by the oxygen sensor. Furthermore, if the cylinder head has ever been changed with an improper head, it is possible that the drilled port will not be there. Identify any restrictions or missing ports if the pump goes on and air is going through the one-way valve but the error continues to show. Rick Muscoplat’s 2015 Rick Muscoplat’s Rick Muscoplat posted a blog entry on

P0491 Secondary Air Injection System Insufficient Flow Bank 1

Cheryl Bowman contributed to this article. Ex-shop owner/operator with insufficient flow through secondary air injection system (Bank 1)

What does that mean?

This is a general powertrain code, which means it applies to all makes and models from 1996 and onward. The particular troubleshooting steps, on the other hand, will differ from car to vehicle. Among the components of this system, which is commonly found in vehicles from the manufacturers Audi, BMW, Porsche, and Volkswagen – but may also be found in other vehicles – are an air pump, an exhaust manifold with an input check valve, a vacuum control switch, an electrical input circuit for the vacuum control switch, and an abundance of vacuum hoses.

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A more thorough combustion of hazardous pollutants – hydrocarbons – is therefore ensured.

If the air pump and check valve are broken, these are usually the easiest components to repair; however, many of the vacuum lines are located beneath or below the intake manifold, making replacement more difficult.

The P0491 code indicates that there is a problem with the system – often, the secondary air flow on bank 1 is too low.

Bank1 refers to the side of the engine that contains cylinder 1. See codeP0492 for more on bank2. P0410, P0411, P0412, P0413, P0414, P0415, P0416, P0417, P0418, P0419, P041F, P044F, and P0492 are some of the other secondary air injection system error codes that might occur.


Among the symptoms of a P0491 engine code are the following.

Potential Causes

The following are examples of possible causes for a P0491:

  • Check valve on the exhaust manifold that is not working properly
  • It is possible that a fuse or switch for the secondary air injection pump is malfunctioning. a malfunctioning air pump
  • Vacuum hose that is leaking
  • A malfunctioning vacuum control switch
  • A vacuum line had become dislodged. A leak in the hoses or piping that connects the secondary air injection pump to the Combi or secondary air injection system
  • Or It is possible that the secondary air pressure sensor is malfunctioning. The combi valve is defective in and of itself
  • Occasionally, carbon will clog the secondary air injection port in the cylinder head of a vehicle. It is possible that the secondary air injection apertures in the cylinder head have become blocked.

Diagnostic and Repair Procedures

The majority of the diagnostic tests must be carried out while the engine is absolutely cool to avoid damaging the engine. There may be a delay in some of the follow-up tests until the engine has completely cooled down again, which will generally take several hours. Some of the tests may potentially generate extra fault codes as a result of their results. It is important to remember to delete all of the fault codes after you have identified and corrected the problem. 1. Make sure the pump is working properly.

  • Removing the pressure hose from the pump or from the manifold check valve, depending on which is more convenient, is recommended.
  • If air is being pumped, proceed to step 4; if not, proceed to step 2.
  • Disconnect the electrical harness connector from the pump’s electrical harness connector.
  • The connection with the brown wire serves as a ground, while the other terminal serves as a positive terminal.
  • 3.
  • The pump harness connection should be tested to confirm that it has 12 volts by testing the voltage between the two terminals on the pump harness plug.
  • You should check the fuses and the relay if you do not have 12 volts.


Remove the pressure hose from the check valve and set it aside for now.

If not, replace the hose.

Is it true that the valve closes and the air flow is stopped after a minute?

Continue to step 5 if the valve did not open.

This indicates that the valve is faulty; nevertheless, it indicates that the vacuum control switch is most likely the source of the problem.

A vacuum pump, which may be found at auto parts stores, will be required for this stage.

If the valve is open, the suction should be released.

If the valve does not open at all, or if it does not close, it is necessary to replace the valve.

Allow for thorough cooling of the engine.

Start the engine by pressing the start button.

If this is not the case, you may be required to take the car to a repair shop since additional diagnostic testing will include the removal of some engine components.


Make a circuit diagram by following the vacuum line from the check valve to the switch.

If you discover any of these issues, replace the hose and repeat the test in step 6.


Attach the vacuum gauge to the input pipe to check the manifold vacuum – while the engine is still running – before continuing.


The valve should be closed, and the pump should not be capable of maintaining a vacuum.

Jumper wires should be used to connect the control switch’s two terminals together to supply 12 volts. If the switch does not open and release the vacuum from the pump, it is necessary to replace the switch entirely.

Secondary Air Injection Video

Despite the fact that we are not linked with the creator of this video, we have included it as an extra resource for diagnosing your air injection problem (s).

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Need more help with a p0491 code?

If you still need assistance with the P0491 error code, please ask your issue in one of our FREE vehicle repair discussion boards. Please keep in mind that this material is being provided solely for informational reasons. It is not meant to be used as repair advice, and we are not liable for any actions you take in relation to any vehicle. All of the information on this website is protected by intellectual property rights.

Dodge Stratus Check Engine Light ON Trouble Code P0491.

What is the meaning of Trouble Code P0491? Problems with the Secondary Air Injection System are indicated by the OBD II Trouble Code P0491. Among the components that comprise the AirInjection System are the air pump assembly, which is composed of a pump, a mass air flowsensor (MAF), a relay, a bracket, and an intake filter. Activated exclusively during cold starts, the air injection system introduces a precisely regulated amount of air into your engine’s exhaust system, assisting in the oxidation of hydrocarbons (HC) and carbon monoxide (CO) emissions.

  1. Through the use of a tube that is attached to the Mass Air Flow Sensor (MAF) and the air filter assembly, fresh air is pulled into the air pump.
  2. The voltage generated by the MAF will be proportional to the amount of air flowing through the MAF.
  3. Afterwards, the air injector pump compresses the air, which is then routed via a tube and through one-way check valves before being injected into the catalytic converters.
  4. Air is only permitted to pass through these valves in one direction, and that route is solely in the direction of the catalytic converter.
  5. When is the AIR Injection system put through its paces?
  6. What is the source of the P0491 setting?
  7. A total of two tests will be performed by the ECU prior to saving a P0491trouble code and turning on the Check Engine Light.



Internal failure of the MAF sensor Fourth, the MAF signal circuit has been shorted to the ASD relay output circuit MAF signalcircuit shorted to battery voltage (number five).

Signal circuit for the MAF is open.

8- The MAF signal circuit has been shorted to the sensor ground circuit (K4).

The ground circuit of the MAF sensor is open.

Faulty PCMBased on the various reasons listed above, it is clear that, while P0491 is connected to the AirInjection System, it is conceivable that a defective Mass Air FlowSensor (MAF) is the source of the problem.

Of course, don’t forget to double-check the fundamentals first. Vacuum lines, intake tube, air injection valve, and other components are broken or disconnected. Simply take a brief visual inspection to ensure that everything looks to be in working order.

Chrysler P0491 Secondary Air Injection System Insufficient Flow Bank 1 – Car OBD Codes

2013 Chrysler Town and Country S, 2013 Chrysler 300 Motown Edition, 2013 Chrysler Town and Country S, 2013 Chrysler 300 Motown Edition 2013 Chrysler 300 Glacier, 2012 Chrysler Ypsilon, 2012 Chrysler Delta, 2013 Chrysler 300 Glacier, 2012 Chrysler Ypsilon, 2013 Chrysler Delta, 2011 Chrysler Town and Country, 2012 Chrysler 300 SRT8, 2012 Chrysler 300 Luxury Series, 2012 Chrysler 300C, 2012 Chrysler 300C, 2011 Chrysler Town and Country, 2011 Chrysler 300, 2011 Chrysler 200 S, 2011 Chrysler 200 Convertible, 2011 Chrysler 200, 2011 Chrysler 200 Convertible, 2011 Chrysler 200, Peapod from Chrysler GEM 2009, The Chrysler 200C Electric Vehicle Concept debuted in 2009.

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Chrysler ecoVoyager Concept from 2008, Chrysler Town & Country (2008 model year) Chrysler Sebring Convertible, model year 2008.

Pacific Coast Highway, Chrysler PT Street Cruiser, 2007, model year A few examples include: the Chrysler Nassau Concept from 2007, Chrysler Crossfire UK Version from 2007, Chrysler Crossfire Roadster UK Version from 2007, and the Chrysler Aspen from 2007.


Among the 2013 Chrysler Town and Country S and 2013 Chrysler 300 Motown Edition models are the 2013 Chrysler Town and Country S and 2013. Among the Chrysler 300 Glacier models are the 2012 Chrysler Ypsilon and the 2012 Chrysler Delta, while the 2013 Chrysler 300 Glacier is the most recent addition. Among the Chrysler 300 models available for purchase are the SRT8, the Chrysler 300 Luxury Series, the Chrysler 300C, and the Chrysler Town and Country, all of which were introduced in 2012. Among the models for 2011 are the Chrysler 300, Chrysler 200 S, Chrysler 200 Convertible, and the Chrysler 200, all of which are available in 2011.

EV Concept from Chrysler, the Chrysler 200C.

Chrysler Town & Country (2008 model year).

a 2008 Chrysler 300C UK version, a 2008 Chrysler 300C Touring UK version, a 2008 Chrysler 300C Touring SRT UK version, a 2008 Chrysler 300C SRT version, a 2007 Chrysler Sebring UK version, a 2007 Chrysler Sebring a 2007 Chrysler Sebring a 2007 Chrysler Sebring, a 2007 Chrysler Sebring a 2007 Chrysler Sebring a 2007 Chrysler Sebring a Chrysler Pacifica (model year 2007).

A number of Chrysler models were introduced in 2006, including the Imperial Concept and the 300C SRT8 Touring.

Chrysler Town & Country (2005 model year).

The 2004 Chrysler Crossfire is the 2004 Chrysler Crossfire SRT6 Roadster, and the 2004 Chrysler Crossfire Road the 2003 Chrysler Airflite concept car, the 2003 Chrysler 300M concept car, the 2003 Chrysler 300C Touring concept car, the 2003 Chrysler 300C concept car, the 2002 Chrysler Pacifica concept car, and the 2002 Chrysler California Cruiser concept car are all examples of concept cars by Chrysler.

OBD Engine Error Code P0491 Solution

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P0491 Chrysler OBD Error Code P0491 Lexus OBD Error Code P0491 Toyota OBD Error Code
P0491 Dodge OBD Error Code P0491 Lincoln OBD Error Code P0491 Vauxhall OBD Error Code
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Chrysler 200 P0411: Secondary Air Injection System → Incorrect Flow Detected

In the case of the Chrysler 200, P0411is an universal OBDII issue code, which means it has the same meaning as it would for any other automobile or truck. It is clear from the definition that the code is informing you that the ECM has identified an erroneous flow rate in the secondary air injection system. P0411: Incorrect Flow Detected in the Secondary Air Injection System (Secondary Air Injection System). Using the secondary air injection system, air is injected into the exhaust to assist in the reduction of exhaust emissions.

However, there are a variety of different reasons why the code is thrown.

P0411 Symptoms:Chrysler 200

P0411 can cause a variety of symptoms and have an impact on the overall drivability of your 200. The following are the most prevalent signs and symptoms:

  • During heavy acceleration, if the AIR system is not functioning properly, the excess fuel vapor in the exhaust might combust.

200 P0411 Diagnosis

The AIR system is composed of three major components, which are as follows: The pump, hoses, and one-way check valve are the components. Checking the fuse for it is a good first step because everything is regulated by electronic means in general. A decent scan tool will allow you to instruct the AIR pump to turn on and off as needed. In this case, you will know that the product has gone bad. Here’s a nice video from Flat Rate Mechanic on how to diagnose this error code:

One Way Check Valve

The failure of the one-way check valve will be the most typical cause of the P0411 error code. When this occurs, moisture is allowed to enter the pump. In the winter, this moisture has the potential to freeze. If frozen water does really cause the air pump to freeze up, it has the potential to blow the fuse that controls it. This fuse is normally located beneath the hood of the car. That’s an excellent spot to begin your search. It just takes a fraction of a second to determine whether or not a fuse has blown.

AIR Pump

In the majority of cases, P0411 is caused by the AIR pump itself. They are quite inexpensive. If they are no longer taking instructions from the ECU, the error code P0411 will be shown on the display.

Exhaust Leak

When there is an exhaust leak, the ECM may believe that the AIR system is not functioning properly. Examine the exhaust system for signs of damage. In the event that there is a leak, you should be able to detect it.


Even though the Chrysler 200’s P0411 code is unlikely to cause the car to break down, its drivability may be compromised. However, once the check engine light illuminates, it’s a good idea to get the vehicle serviced as soon as possible. If you have anything to contribute, please leave a remark in the section below. Thanks for reading. Wishing you the best of luck!

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