My truck/SUV hesitates when I press the accellerator and now one of the vacuum lines pops-off if too much accelleration too fast. What is wrong?
Auto or manual transmission? What year Expedition and how many miles? Which vacuum line “pops-off”? Has it had all the maintenance listed in the owner’s manual since new?
Auto Transmission, 2003 5.4L 125000 miles - regular service up to date through 90000 miles
Is this pop-off vacuum line going to a valve cover or the PCV valve?
If so you might have a clogged breather hose, or broken or worn rings, causing pressure to build up in the crankcase.
the metal tube that this hose connects to appears to be going into the exhaust mechanism below.
High exhaust pressure and hesitation could be a plugged cat converter.
Thank you for all of your help