cbroche10

Where is the Air Check Valve on a 2006 Chevy Cobalt?? Also may need to know where the air pump is as well. My wonderful car is shuttering and I am being told that the Secondary Air Injection Sensor is bad and that I need to replace the Air Check Valve and I have no idea where it is.

BHBarr

First, you'll have to pull off the big plastic cover from the top of the engine (remove your oil fill cap first). The secondary air check valve is behind the top of the engine. It looks like a short canister, with electric connection on the top and a rubber hose coming out to the right.
The air pump is at the bottom of the engine compartment, between the bottom of the radiator and the bottom of the engine.
It sounds like your check valve is frozen in the open position, which allows exhaust to get sucked through the lines to your air filter intake, which causes your drivability problems.

cbroche10

Thanks,

Sounds like it should'nt be that hard to replace myself.

BHBarr

No, it is not that hard to replace. It's probably best to get the new part first to make sure which bolts you have to remove. Also, make sure you get the gasket between the valve and the exhaust manifold - the old one will get damaged when you remove it.

cbroche10

Is the part called a Secondary Air Check Valve or is there a different name for it? I have asked a few parts stores and they act like they don't know what I am talking about.

BHBarr

Yes, the part is called the Secondary Air Injection Check Valve. I was not able to get it through parts stores - I had to go to a Chevy dealer. It cost $255 plus an extra $5 for the gasket.

cbroche10

that is an expensive part. Hope it does the trick. I heard that there is a service update on the ECM and the injector modules on that car as well. Of course GM tells me that they have not heard of any issues with the car and they act like I am the first person that has ever had any issues.

BHBarr

It is an expensive part. If you are not sure if that part is bad, you may want to do some additional checking. I have had to replace the air check valve twice and the air pump once on my 2006 Cobalt. The first time, 2 years after buying the car, the air check valve was stuck open and I got the service engine soon light and the car ran rough at idle and accelerating. Trouble code was P2440. I replaced the valve and the car ran well for 9 months, then got service engine soon light again, but car ran OK. The air pump was full of water and rusted tight. Replaced that and ran well for another 6 months, then got service engine soon light, but car ran OK. This time trouble code was P0411. The valve was stuck shut this time. Since it was running OK, I left it alone until I failed my emission test a couple months ago. I have now replaced the valve a second time and it is running well.
I think with either the valve stuck shut or with the pump not working, you will get the service engine soon light, but the car will run OK. But when the valve is stuck open, it allows exhaust to backflow into the lines and causes rough running.
This system only operates for 30 seconds to a minute when the engine is cold and has been shut down for at least one hour. The valve opens and the pump pushes air into the exhaust to help the catalytic converter while it is cold. The valve then shuts and the pump turns off.
You may be able to check the components by disconnecting the rubber hose where it meets the valve. Let the car sit overnight. Then, get someone to start the engine for you. If the pump is working OK, you should feel air coming out the rubber hose. By looking in the opening where you disconnected the hose (you may need a mirror), you should be able to see the valve open and then shut, if it is working OK. As I said above, this only happens for about 1 minute, and only with a cold engine that has been sitting for at least an hour.

kjf213

I am having the same issue right now. I had the valve and the pump replaced today, and the light came back on about an hour ago. I'm getting so frustrated with this thing!!!

David Cutrona Jr

I have my check engine light on for my secondary system and I already know why, I knew why when it went on. If you have an aftermarket intake, especially one that doesn't filter the air it draws in then that could simply be your problem, and eventually could cause other problems