I own a 97 chrysler LHS with the 3.5 liter v6. with P0401 EGR insufficient flow

What is your question?

I user to be an auto tech by trade. I need to find the troubleshooting diagnostic tree for a 97 LHS with the P0401 code. The engine stall at idle while applying vacuum to the EGR valve. Need help finding the diagnostic tree for this vehicle. can anyone help? Thanks, Leon