The PCV hose may crack, causing the vehicle to idle roughly, this may or may not illuminate the Check Engine Light.Google+
Car Problem Reports
Ford Expedition Rough Idle Due to Cracked PCV Hose
Ford Expedition Problem
Engines Affected: 4.6L V8, 5.4L V8
Average Mileage: 149,002 mi (122,100 mi - 208,000 mi)
Visitor, 2000 Ford Expedition, 5.4L V8, 136,000 mi
Rough idle, stalling on my 2000Expedition. Code came up as PO171. Found a leak in my PCV hose at bend. This is a Ford only part. Went to local Ford dealer and ordered the hose with the PCV valve included. Replaced it myself. Problem solved.Ford part # 2L1Z6758GA.
Visitor, 1997 Ford Expedition, 5.4L V8, 122,400 mi
replaced entire pcv hose assy including valve
Visitor, 2000 Ford Expedition, 4.6L V8, 208,000 mi
idled roughly, would die after idling for a few minutes, but when going down road would drive fine. pcv hose broken and was replaced, fixed problem
Replaced with Bulk Fuel Line and resolved issue
Visitor, 2002 Ford Expedition, 5.4L V8, 130,340 mi
Pvc line busted. broke air leaking car goes death if you don't press the gas.
Visitor, 1997 Ford Expedition, 5.4L V8, 155,982 mi
I had extremely rough idle and most of the time it would not idle. I replaced the PCV plastic line with rubber hose. It has fixed the problem.
slight missing at idle. getting code p0171 and 0174. firstname.lastname@example.org