I got my secondary air monitor to pass! It ended up being the check valves were clogged! I ended up just throwing the parts at it because I suspected they were I knew my pump was working and blowing strong because I ordered a new one and it blew less air!
Valves are ~$25 each on Amazon or parts geek!
They were difficult to get off pretty seized had to continually hit them with break free lube on separate attempts just make sure you have the right tools a 1” and a 7/8 wrench. You’ve got to position yourself to get the two opposing forces to get torque and break them free without busting the down tube to header.
What a pain from a OG tech at the Chevy dealership telling me I needed a new air pump, no check engine light for info one shop had pulled the hoses to check the valves but didn’t find any debris, buildup or moisture behind them so thought they were good..
If you know your pump is good it’s worth pulling the check valves just to make sure they’re clear (if you can’t blow through them they’re toast) after 150k there’s bound to be buildup! Don’t forget to confirms small vacuum hoses are good!
