I have a 2002 Monte SS with a 3.8. Car has been setting for a year doing body work. When I started the car my check engine light comes on. I am getting a P0170 fault, too lean. I have repaired three vacuum leaks, one in the hoses, one on the MAP gasket, and one on the upper intake. I have pulled the EGR valve and cleaned it. The valve is working and the gasket is new. I pulled the MAF and cleaned it also. I took the car to the Chevy dealer for him to diagnose. Said I had a faulty secondary air pump which was seized and blowing the fuse. The pump was seized up and I replaced it and the fuse. Still have the check engine light on. Any thoughts from anyone on what to do?

Have you sprayed carb cleaner around all the intake mating surfaces?

Did you have the DTC'* cleared after replacing the pump/fuse?
If not then you may have to wait a while before it actually goes out on its own.
I'd have somewhere like autozone use their Actron scanner to reset the DTC'* for you, then see if the DTC comes back.

Another thing to check which often does not set a trouble code... Check your Coolant Temperature Sensor (the one that reports to the computer, not the one that operates the gauge). I've had three cars with faulty CTS, two ran rich all the time because they never told the ECM that the engine had reached operating temp (therefore running open loop continuously) and one that reported engine was ALWAYS at operating temp (never running open loop as it should when cold).

In all 3 of these instances, I never had a SES light illuminate, and no codes were stored. Might be something to look at, and anyone with a scanner should be able to see if the engine is in open loop or closed loop when the engine has been run long enough to be at normal operating temp.