E 350 ford were is the mass air flow sensor located?? on 1994 Ford E-350

the computer shows mass sensor not working engine runs rough stalls out this is a 5.8 ltr vans can be hard to work on nothing is in same place as the truck

Asked by for the 1994 Ford E-350
you have a map sensor in that yr and its mounted on the firewall, you have a 3 wire pigtail and 1 vac hose to it, ck to amke sure you have a good vac at sensor