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That hose is NOT a vacuum hose. Its a pressure supply hose and holds pressure when the pump is running. There is a plastic coupler in that hose near the alternator area. You can disconnect it and with a cold engine see if the pump is running. It puts out a good flow of air when the pump is running. The air comes out of the hose going to the front of the car.
All the AIR system does is supply air to the exhaust system through the exhaust manifolds during cold start to help light off the CATs. Its all about meeting an emissions standard. To pass emissions, you will need tp resolve the issue OR tune it out.
The hard line coming from the manifold is lightly sucking air which leads me to believe the check valve is working, or at least it's allowing air TO the head. It's not very much suction but it's there.
The soft tube coming from the splitter that goes up towards the pump is pushing air. Not a massive amount but again enough to be noticeable.
That bottom picture the large hose comes up the driver's side of the car, through a splitter, into the left manifold with a check valve and a hard line making an S-turn into the manifold.
That's where I pulled the hose. The head is sucking and the hose is blowing air at a decent clip, enough to notice but not gale force winds, either.
I didn't test the passenger side, I'll do that in the morning when it's cold again.
Given the head sucks slightly I'd say the check valve works. Given there is pressure on the driver's side I'd say the pump works. If there is pressure and suction on the right hand side as well, then I'm stumped as to what the problem is...???
I’m getting confused with all this “sucking and blowing” but the hose that comes up from the pump is the outlet side and I don’t know what you mean by the “head is sucking” ????...the pump can operate but if the PCM doesn’t energize the solenoid you don’t know if the shut off valve will open allowing the air into the intake manifold...I’m lucky to have a bi directional scan tool and in the picture you can see the upstream O2 sensor go lean (low)....this is what the PCM expects to see (below 222mv for 1.2 seconds) and if this is not seen you’ll get the P0410...I’m able to energize the AIR solenoid with the scan tool but the PCM only energizes it for about 2 seconds and that’s it....now you can jump the load side of the AIR PUMP relay to run the pump but you would have to access the solenoid electrically OR apply vacuum there to allow the SOV to open...diagnosing these DTC’s takes a little knowledge and sometimes some special tooling...as long as you know the pump operates basically you have to determine that the solenoid and SOV are working !!...you may even have “lazy” O2 sensors...the other picture is the output of the pump on the LH side. Both O2 sensors go LEAN when the solenoid is energized...the short term fuel trims go rich (add fuel)
I'm checking the air flow at the TOP rubber hose in that 2nd picture of yours. After the splitter. I'll have to wait until I'm not going somewhere and dressed appropriately to mess with it again.
The sucking is easy.
If you put your hand over the ENGINE side of that metal tubing where it goes into the head, you can feel the head sucking air in. This is a normal function of engine flow being pushed out the manifold into the exhaust. That's how you know if that metal check valve is actually allowing air into the head.
I'm getting air, so that's not the problem which is why I'm trying to move on to what to check next. When the car is started that rubber tubing you have pictured there IS PUSHING AIR. Not enough to keep my finger from being able to plug it but enough to hear it when my finger starts blocking it.
So what do you check next? Or does anyone know anyone in the Nashville area who can tune this damn thing out. It's useless. A cow farts more greenhouse gas than this system produces on startup.
Like I had said if you know the pump works you will have to concentrate on the SOV at the pump or the solenoid which is near the PCM...don’t know what else to tell you...if you have a vacuum pump like a Mityvac you can apply vacuum to the SOV to see if it operates...you can jump the solenoid to see if that works...unless you want to pay a shop just for their diagnostic time and replace any bad components yourself !!!
The HEAD has nothing to do with this system. If you look where the check valve connects to, It goes into the top of each exhaust manifold. Most of the time you get this DTC, is because the PCM does not see the change in O2 sensor response when the PCM calls for this test to run.. One of the things that prevents this is the actual check valve.
Inside the check valve there is a rubber disk seal that the AIR pump air supply deflects to push air past the check valve and into exhaust manifold. If that rubber disk diaphragm seal is old and hard. it will not deflect and allow enough air into the manifold to change the O2 sensor readings. . The PCM expects to a very specific change and if it does not, it will throw that DTC.
The PCM test that C5 DIAG displayed is a sure way of seeing if the AIR air flow is working and changing the O2 sensor response that the PCM is expecting to see during that period of time. The PCM runs that test while you are driving when the engine meets specific parameters just to insure that the AIR system is function properly.
Many years ago before I actually disassembled a check valve, I assumed that the check valves used a spring loaded valve to control air flow. When mine acted up, I sprayed Brake Parts cleaner into the hose followed by WD-40 and forced it into the check valve with compressed air to see if that would free up the check valve parts. Not knowing that it used a rubber diaphragm disk to seal against the back flow of exhaust.. It worked probably because the brake parts cleaner softened up the rubber disk that makes the seal and the flow of higher pressure compressed air maybe flexed the rubber disk a little more than normal. Now I know that this sometimes works and only for a very short period of time. I recommend just changing out the check valves if they are the source of the blocked or low air flow into the manifold.
Its a bit of work but try disconnecting the check valve from the exhaust manifold and see if ample air is flowing past the check valve when the pump is running.
