Five Signs That Your Secondary Air Injection Pump Is Not Working

In modern vehicles, there’s no getting away from emission standards. They are required by every auto maker to comply with them. This means they must install extra components in your vehicle.

The secondary air injection pump (also known as the SAI pumps) is one of these components. While the secondary injection pump can do a great job of lowering emissions, they tend to get worn out over time.

When that happens, you’re going to start noticing a variety of symptoms, and the longer you leave them alone, the more severe they’ll get. That’s why we broke down the most common symptoms of a faulty secondary air injection pump here before diving into everything else you need to know about these nifty components.

A failed emission test or check engine light are the most obvious signs of an air pump problem. But while those are the most common symptoms, they aren’t the only thing you need to look out for.

Below we’ve highlighted the five most common symptoms, so you know what to look out for if you suspect a bad secondary air injection pump.

Bad symptoms of secondary air injection pump

1. Verify Engine Light

Your vehicle’s manufacturer fills it to the brim with sensors, and these sensors monitor just about everything that your car does. So, it’s no surprise that if you have a faulty secondary air injection pump one of these sensors will tell the ECM to let you know through a check engine light.

The most common code you’ll run across is a P0410, a Secondary Air Injection System Malfunction. You might get an error code from your oxygen sensor, or catalytic convert. If that’s the case, you have a check engine light because of one of the symptoms, not the cause.

That’s why it’s always best to hook up an OBD II scan tool to your vehicle when making diagnostic repairs – that way, you diagnose the problem correctly the first time.

2. Failure to Pass the Emissions Testing

Your secondary air injection pump is an emissions component, so it’s no surprise that if it’s acting up, you’re not going to pass an emissions test. Your catalytic converter can perform better if it has access to more air.

If you have an emission-related check engine lamp, many emissions tests will fail. While we’ll dive into how this component works later on, just know that if it’s acting up, you’ll never pass an emissions test – even if you don’t have an active check engine light.

3. Slow Acceleration

Your secondary air injection pump monitors the hydrocarbon levels coming out of the engine, and if it’s getting the wrong readings, it can tell your ECM that something isn’t going right inside the combustion chamber. Performance problems such as slower acceleration can result.

4. Low Power Output or a Stalling Engine

A stalling engine, or reduced power output are two other possible performance issues that could be caused by errant secondary air pump readings. Because your engine's performance is being affected by errant readings from the secondary air injection pump, this can lead to engine problems and even stalling.

You should replace the secondary air injector pump ASAP. If you don't, your driving problems could become more serious.

5. Idle at a Low Level

A low idle is sometimes the main performance issue. That’s because as you press the accelerator, your vehicle produces more hydrocarbons, which can be enough to get the sensor working as it should. The ECM will send the proper readings back to the engine.

The problem is likely to continue for longer periods of time, so it's important that you don't delay.

Secondary Air Injection Pump Location

The secondary injection pump is located usually on the engine, or in the engine bay. Sometimes it may be hidden in the engine bay but most often you will see it on the engine.

Look for something similar to the one shown above. This hose goes to the intake. Follow this hose.

What is the Function of Secondary Air Injection pumps

A secondary air injection pump reduces emission by pumping air in just before the catalytic convert.

While this might seem like it’s cheating the emissions system by lowering the percentage of hydrocarbons in the exhaust, that’s not how the testing works, and it actually increases the number of hydrocarbons your catalytic converter can convert into water.

Simply stated, more exhaust air means more catalytic conversion efficiency.

Prices for Secondary Injection Pump Repair

Average replacement costs of secondary air injection pumps are between $250-$400. This will be significantly less expensive than purchasing a replacement primary air pump that can run from $600 to $7500.

Keep in mind that the exact cost for your vehicle’s repairs will vary depending on what you drive and where you take it in for repairs.

If you’re looking to save a little money when you’re replacing your secondary air injection pump, you can swap the parts out yourself. The parts cost $200-300, and the labor is usually less than $100.

But if you can jack up your vehicle and reach the secondary air injection pump, then the job itself is relatively straightforward, so it’s not hard to save a little bit of money. Just make sure that you properly jack up and secure the vehicle so you don’t get crushed while swapping the parts.