how much will it cost to replace an EGR circuit with the diagnostic code of P040 on 2001 Oldsmobile Alero

The check engine light keeps coming on

your missing a number after the 0. we need that number to help you.

Ok its P0401....thank you!
that is a code for insufficient flow. you need to verify that vacuum and exhaust are getting to the valve before jumping to any conclusions. I would have a shop verify this and give you a pin point reason for the failure.