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
Engine Affected: 5.4L V8
Average Mileage: 134,947 mi (122,100 mi - 155,982 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, 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. email@example.com