My 2003 Z06 with 113k miles keeps throwing the code p0410. I read a bunch of older threads about it. First I tried spraying wd40 into the hose that goes from the air pump to the check valve and pushing it through the line with compressed air. That didn't help. Yesterday I replaced the secondary air pump. That didn't help and it threw the code again after I reset it. The pump turns on and works at start up.

Any other suggestions to fix this before I have to take it to a shop and pay someone else for what I could probably do myself?

 

First off I would check for any DTC's (trouble codes) with a scan tool or through the DIC. There are 2 separate DTC's for the check valves which are P1415/1416 which you may not have. A P0410 is a "system flow" issue...It's good that you can hear the AIR pump run at engine start up

...did you hear it previously at start up before it was changed. what you have is a vacuum operated shut off valve at the pump and I'm not 100% sure if the SOV is part of the new air pump assembly...when the air pump comes on if the SOV does not open by vacuum the pump air flow will not enter the exhaust manifold...I would see if you have vacuum at that SOV when the air pump turns on. Now there is a solenoid which controls the vacuum to that SOV and you have to see if that is working...the PCM applies a ground internally to complete that circuit that allows the solenoid to function and allows that vacuum to be applied to that SOV. You might also have a vacuum leak someone in the system too...the solenoid sits above the PCM so it is not really hard to access...so you may have a bad SOV, solenoid, vacuum issues, or electrical wiring issues !!...this is the wiring from my 2001 !!...my money is on a vacuum leak...if you had a scan tool I would think your fuel trims would be somewhat elevated depending where in the system the vacuum leak is located !!...the vacuum line I believe originates from the vacuum reservoir.
EDIT: with a P0410 what the PCM is looking to see is that BOTH O2 sensor voltages drop (goes below 222mv for 1.3 seconds) when that air is injected into the exhaust manifolds...basically it is looking for a lean condition...if it doesn't see that... BOOM...a P0410 !!

 

So is replacing both 02 sensors the next step? I only have P0410 and that's all it ever trips.

 

NO NO NO !!!....why does everyone want to change O2 sensors ??...LOL !!!!...

it's not an O2 sensor issue my friend !!...you have to see why there is no airflow into the exhaust manifolds from the air pump....if no airflow into the exhaust manifold the O2 sensors don't go lean !!!!....first look for vacuum at the SOV when the pump kicks on during initial start...like I said previously when the PCM commands the solenoid to be grounded and the solenoid opens it applies vacuum to the shut off valve on the air pump and that allows the airflow from the air pump to enter both exhaust manifold tubes...do you get it ??...I'll include the description and operation for you...I also highlighted a few things !!...also you may have to clear the DTC to do the testing...sometimes if a DTC is present the PCM will not allow the system to operate !!

 

After reading about the check valves... When I disconnected the hose that goes from the pump to the check valve, there was air coming back from the exhaust manifold and it made the rumble sound from the engine. If the check valve is stuck open would that trip the code?

 

So you disconnected the hose (shown by the arrow) and you heard some kind of exhaust sound ??...leaking exhaust through the check valve may create more air pressure inside the hose than what the pump delivers (I never measured that..maybe I will ) so yes, it may keep both O2 sensors from going lean....hopefully it is just the left side check valve so try shooting something like Brake Kleen through it a few times...the right side is behind the intake manifold so see if cleaning the left side works and if not shoot it over to the other side...I'd see if you do have vacuum at the SOV too !!...I have an exhaust back pressure gauge that I can hook to the exhaust fitting...I'll see what it reads !!

 

To satisfy my “Corvette Curiosity” I decided to look into the AIR system...I removed the AIR pump supply hose and there is 1 psi of air pressure with no check valve installed...with the drivers side check valve installed I had to use a manometer from my smoke machine to measure the pressure...I believe it was around .126 psi !!...the exhaust pressure had only .108 psi at 3000 rpm !!...could not even read it at idle...if your 0410 clears by cleaning the check valve keep us updated...I believe cleaning allows more airflow through the valve and not by allowing flow out of the exhaust manifold !!

 

I had previously shot wd40 and pb blaster into the air hose that goes from the pump back to the first valve. I then used compressed air to blow it back into the line. When I ran the car it smoked a lot as the PB blaster came out the exhaust. It made no difference and the code just came back.

On a negative note. My car registration bill shower up today and I have to smog this year. So I need to get this check engine light to stop coming on long enough to pass smog.

 

Well like I said we need to verify that when the air pump comes on you can feel
airflow to the check valve...I will try to remove the LH check valve and run the pump airflow directly to the exhaust manifold and see what happens !!...oh, and when I checked my O2 voltages with the air pump running my O2’s went RICH !!...HUH ??...they should go LEAN...less than 222 Mv !!...but I have no trouble codes !!

 

Update..
I replaced the valve next to the driver's side of the engine and the valve down next to the air pump. The inside of the one by the air pump was eaten up inside by the exhaust getting through the other valve and heating it up I assume.
I cleared the check engine light, drove a little over a hundred miles over a few drive cycles. I took the car in and got it smogged and it passed today. Mission accomplished

 

Watching all this AIR pump business. Curious what was done when ECS installed my ARH headers. The pump still runs - but wondering if I can just disconnect the power to it as its probably been "tuned out"....

 

Mine throws the P0410 code also. I simply do the following: reset the code and go for a long ride before you go to the smog tester. Don't shut the engine off if you can avoid it while in line. The worst that happens is the PCM is "Not ready" and you will have to come back to the tester. I was able to get it passed in Maryland. A car from MY 2000 is allowed one fault but not two in the test.

 

So this forum has helped me a lot on my own 0410 code, however all the the tips i read on this subject did not solve my issue. I started with the air pump fuse, it was good, did the check valve test and clean, it was good. I moved on the next and removed the air pump and vacuum valve and manually tested both, both good. Next went to the vacuum switch in the upper right fender, just replaced it because it was so hard to get to. No luck, I forgot to mention the air pump only runs on a cold start, we have had the warmest summer in history no no days below 70 degrees which is what a cold start is to the ECM. Meanwhile I cant get my monitors to set because the air pump not the O2 heaters are coming on. I decided to start over again and by accident I found the relay in the the fuse box labeled air pump. I swapped it with my horn relay and guess what, the horn did not work. New relay and a 65 degree day got my monitors to set and problem solved. FYI this would be the second relay to fail, first was the fuel pump, thankfully this forum told me to swap with the horn relay and drive home.