2000 Ford Escort stalls when downshifting

Do you have trouble starting the car back up and will it stay running without having your foot on the gas? Do you have any other symptoms (rough idle, lack of power on acceleration, etc.)?

Does it die if you step on the brake with the car coasting in neautral? Manual trans has no "give" between engine and drivetrain like an automatic, you may be killing engine depending on what gear you are shifting to

no, to your question,
I will be driving like 60 and slow down for a curve or turn and downshift from 4th to 3rd and it dies
I have driven a manual transmission since I was 16 just turned 50 so I know if I kill it. that is not the case.
It starts right back up. I have not noticed any lack of power

Have you had it scanned for codes to see if th ePCM stored anything? Autozone will do it for free

no but thanks that is good info to know
any other thoughts?

Does it ever idle erratic? Im thinking maybe try cleaning the throttle bore around the butterfly and the IAC motor. The IAC (idle Air Control) might tbe "lazy" and this could cause what you describe