My wifes car started and idles fine but she hits gas and it stalls :(

Do you have a code scanner? Need to read the vehicle's computer to see what trouble codes (if any) have been set. May be best to call a local shop to get the issue diagnosed. Might save you the trouble and money of throwing parts at it! http://repairpal.com/mercedes-benz-within-10-miles-of-stevensville-michigan-49127