I have a 99 Z28. 65k miles. Got a problem w this code again. Confirmed working is the air pump and check valves. I replaced the SAI solenoid valve. According to my GM factory repair manuals, the only thing left to check is for a breach in the hoses. A vaccum leak. The book says to check the hoses running from the solenoid valve to where the hose splits to the 2 check valves. Is their anything I'm missing? I've cleared the codes after replacing the solonoid valve. I'm guessing I've got a hidden vacuum leak somewhere? Anyone else had this issue where things are working but the SES is on anyway? No other codes on. Just the one. I've yet to check for any vacuum leaks.

 

I recently went thru this 410 code on a 2002 SS camaro. It was intermittant so it was hard to diagnos. I ended up replacing everything (Pump, divertor valve, check valves and solinoid) to keep the light from comming back on. You did not mention your divertor valve. Have you checked to see if it could be divertor valve?

 

if by diverter valve you mean the secondary air injection solenoid valve then yes that is what I replaced. I diagnosed this valve bad using the GM original service manuals a very expensive scanner and a good multimeter. GM books do not call it a diverter valve. The books call it the Secondary Air Injection Solenoid Valve. They mentioned nothing of a diverter valve. I heard this term diverter valve from people, however the books refer to it as a solenoid valve not a diverter valve. so if that's the valve you mean, the one that is inside below on the driver side fender underneath by the air pump, yes, that is the secondary air injection solenoid valve. I forgot to replace the fuse after replacing the valve so I was confused as to why my light was coming back on. Once I replace the 25 amp fuse, the CEL light never came back on. It was simply a bad solenoid valve for me. But I should mention my original codes that came up we're not code 410. My original codes were 412 and a couple of other codes indicating that I had a bad electrical component in my secondary air injection system. Once I replaced the secondary air injection solenoid valve and I forgot to replace the fuse a new code came up and the code changed from 412 to 410 because now I had a good solenoid valve but I had a broken fuse line. in the future you can simply check the air pump by listening for it to kick on and off in the first 2 to 3 minutes that you start the car when it is cold. you will hear that pump kick on and off within 2 to 3 minutes. and then easy way to check the check valves is to simply pull one out and blow into it you can blow into it one way but not the other way it is working properly check both of them this way. generally those valves are supposed to go bad first according to the books since they are supposedly the first piece in the line of defense when a part is going to wear first. so the book says to check those check valves first as they generally go bad first. I hope this helps you