P0410 code

[BIGAL131]

I have a 2002 Monte Carlo SS with the 3.8 litre 6 cyclinder engine. While driving a few weeks ago my check engine light came on so i took it to my local mechanic and he did a diagnostic on it.It came up with the P0410 code which was a secondary air pump circuit issue.Turns out that the secondary air pump was not turning on when its suppose to after checking all the involved operations.I replaced the secondary airpump unit with a brand new one from Delco... and mind you there was no water in it...it was dry.My mechanic cleared the code after installation and all was good for about 1 week. I can hear the secondary air pump working when first starting the vehicle when its cold....it comes on for about a minute then shuts off. A week later the check engine light comes on again while driving with no effect on performance or starting. I took the car back to my mechanic and he checked for codes again and there were none but only a history of codes was showing.
I took it to my local Chevy dealer where they did a diagnostic on it and found no codes but only a history and they deleted it and also checked everything in line and told me that all was working as it should and I should have no more problems.
Aprox 2 weeks later the light comes on again...took it back to the Chevy dealer...now they tell me that i need an upgrade kit for the secondary air pump to reposition the air intake hose as to not let water get sucked into the pump..but that wasnt the original problem( no water in pump) they wanted a total of $350 for this supposed fix but i told them that it wasnt going to fix this (just replacing the air hose with a longer one and mounting it in the fender) After leaving the dealer in discust the light goes out...stays out for 2 weeks and then comes on again last night while driving.I replaced the airpump relay because a mechanic friend of mine suggested i do that but that didnt work!
I would appreciate some good advice on this issue so that i can fix this problem...Code keeps coming up as P0410 but the car runs fine!

[danielsatur]

Suspect - fuse, relay, air pump, stuck or leaky vacuum valve solenoid, air hose, or restricted air passage.

Also check similar threads at the bottom of yours.

[BIGAL131]

Thank you Danielsatur for your reply to my thread....I replaced the Air pump with a new one...also replaced the air pump relay which was working anyway...Dealer tech checked all components including the solenoid and the vacuum valve...the fuse is good so I'm confused as to what is causing this....after a few start ups....the check engine light goes out for a few days and then comes back on while driving...also i didn't mention that when the check engine light comes on especially at night..all the lights including my headlights flicker for a few seconds.(almost looks like a heavy electrical load)...then stops flickering when the light comes on.

[danielsatur]

Ficker of Lights!
How old is your battery?

Any local Auto Parts store could do both a load test on your battery + alternator.

That flicker of lights, might be when the air-pump kicks in.

Keep an eye for other symptoms:
Doe's it happen during rain, after car wash, and snow conditions?
A temporary short, because of water roll onto an electrical connector could trigger the DTC.
Clean and use dielectric grease on your electrical connectors.

[BIGAL131]

I have the top of the line Delco battery for the Monte....3 years old...it doesn't matter if its sunny or rainy it happens...more noticeable in the evening when the headlights are on. I thought the air pump only came on when the engine was cold and not operating temperature?