Skip the auto shop - Our mechanics make house calls

Symptoms of a Bad or Failing Air Pump Check Valve

The secondary air injection system is an emissions system equipped on many road going vehicles. It is composed of several components that work together to reduce the vehicle’s tailpipe emissions. One of these components is the air pump check valve. The air pump check valve is the valve that allows air supplied from the air pump to be pumped into the exhaust stream to reduce hydrocarbon and carbon monoxide tailpipe emissions. It functions as a one-way valve, allowing the air to pump through into the exhaust, while preventing the exhaust fumes from leaking into the secondary air injection system.

When the air pump check valve fails, it can lead to a variety of problems, notably a significant increase in the vehicle’s tailpipe emissions. Usually, when the air pump check valve fails, it will display a few symptoms that may alert the driver of a potential problem that should be inspected.

1. Exhaust fume odor

One of the first and most common symptoms of a bad or failing check valve is an exhaust fume odor. The odor is a result of exhaust leaking either from the valve housing, or through the actual check valve back into the secondary air injection system. The odor may become most noticeable at idle speeds. Any sort of odor indicates an exhaust leak, which compromises emissions.

2. Failed emissions test

Many states require their road-going vehicles to pass an emissions test in order for the vehicle to be legally operated. If the air pump check valve fails, it can significantly impact the tailpipe emissions of a vehicle. The air pump check valve works to reduce hydrocarbon and carbon monoxide emissions of a vehicle, so when it fails, the levels of these two pollutants will increase.

3. Check Engine Light is On

Another common symptom of a failed air pump check valve is the Check Engine Light coming on. When a problem is detected by the vehicle’s computer, it will set off a code and activate the Check Engine Light. Having the vehicle scanned for trouble codes can reveal if there may be a problem with the air pump check valve that needs to be addressed.

As the air pump check valve is part of the vehicle’s emissions system, is it is very important that it functions correctly so that the vehicle can remain at acceptable emission levels. If you suspect that your air pump check valve may be having a problem, or your Check Engine Light has come on, have the vehicle diagnosed by a professional technician, such as one from YourMechanic. They will be able to determine if the vehicle needs an air pump check valve replacement, or if another repair needs to be made.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...


Related questions

Q: Secondary air pump.

The air pump supplies the catalytic converter with extra oxygen so that it can efficiently catalyze any unburned fuel. On start up, the catalytic converter is cold and requires some help to quickly get up to temperature allowing it to...

Q: Emission garage

For this issue you should have the engine scanned to see if you have a code that can be diagnosed. You may have a problem with your Exhaust Gas Recirculation (EGR) valve. The EGR valve may just need to be...

Q: Does my Honda Odyssey 2005 touring carry a smog/air pump? It makes a "Jake brake" kind of sound when the ECO light comes on! 2005 Honda Odyssey

Hello - your Honda Odyssey does indeed have a secondary air pump on less than 6 cylinders to save fuel (ECO=economy mode). Perhaps there is a hole in an exhaust system component which is causing the unusual noise, or the...