Wednesday, January 7th, 2009 AT 4:03 PM
Hello. I have a 01 f-150 v6. It has two codes. 171 and 174. It runs real rough. Smooths out under hard acceleration. Seems like two or more cylinders are misfiring. Any sugg? I don't think itsthe MAF because it seems to be working properly. Vacuum leak at intake manifold elbow?