i have a2004 ford expedition 4.6... with 72000 miles... the other day it started to idle very ruff and then stall when at a stop. check engine came on so i took it to auto zone to read codes... it threw 2 o2 codes. I read on a fourm that if the PCV valve is bad, it can thow false o2 codes... i bought a new PCV. but dont now how to install or where... also could it just be an issues with the mass air flow sensor or egr ? its seems that it would be rare for two o2 sensors to fail at the same time... please help
Mar 24, 2011 at 2:25 AM