The DPFE or PFE sensor costs about 90 dollars and takes only 10 minutes to install - it has 2 vacuum lines pressed onto it. But you need to be sure to erase the codes, road test it and test it again. It won't cause any immediate harm, as the EEC system in your car will compensate for the PFE not working properly, but this does strain other sensors in the system. Best bet - replace it as soon as you are able to.
"Life's too short to drive slow!"
My first name is Anne - was a Ford Dealer Service Manager for 11 years. Waiting for my new Expedition to come in (woo hoo!)