My '02 Z06 has been throwing a check engine light and a P0410 error code recently. Everytime I reset the code, it comes back within the next 2 or 3 driving cycles. I have Stainless Works long tube headers, and a Vortex rammer intake, and had it dyno tuned by LAPD. However, I don't think these mods are contributing to the problem, as I drove at least 2k miles with these mods without any error codes.

I've noticed a pattern with when the check engine light comes on. There seems to be some large electrical load placed on the system, which I think is the AIR pump. Here's the scenario of what happens before the CEL comes on. I'll be driving home from work, and about 15 minutes into the trip, at highway speeds, I'll notice the headlights dim a bit for about 2 seconds. It'll be fine for the next minute or so, then the lights dim for 2 seconds again. It seems like it does this about 3 or 4 times, then the check engine light comes on. Once the check engine light comes on, there is no more headlight dimming.

My theory is that the light dimming is the computer turning the A.I.R pump on, and either the pump is seized, or there is a blockage somewhere in the tubing, or one of the check valves going into the headers is stuck closed causing backpressure and strain on the pump. Without the air pump working or injecting air into the exhaust stream, the O2 sensors detect that, and the computer throws the code.

So my question is, how do I diagnose what the specific problem is? I know the check valves have a tendency to fail on these cars, but I how do I test them? How do I test the pump to see if it is working properly?

Thanks in advance for any help/advice you can give.

 

STINGRAY

We have mirror cars!! I too have an EB Z06 and the Stainlessworks system!! I LOVE IT! I had the same exact problems!! I am still under warrenty and took my car into the dealer! At first they tried to BS me and say that the exhaust system "BACK PRESSURE" was causing the problem!!
We had words!! I asked them to do a TECH II system check out on the system and make sure that the system was working normaly. So,,,,,they agreed and found the Check Valves to be sticking and agreed to change out the check valves on the manifolds. But if that did not fix it, there was nothing else that they could do due to the headers! I agreed! I have not had any problems since.

If your car is in warrenty, you might use the same reasoning with GM.

If not, disconnect your rubber hose that supply air to both valves (Drivers side) and start the car. You should have good pressure for the period of time that the pump is suppose to run. If that is good reconnect the hose and:

Then remove both check valves and then reattach them to the rubber air supply hoses.

Plug the pipes that are open to the exhaust manifolds, start the engine from a cold condition and check to see that you get good air flow from the check valves upon initial start up.
While the check valves are off, clean them out with some carb cleaner.

If you need any more assistance, I can dig into the books for specific details and take pictures for reference if you need them..

Bill