i have a1999 ford f150 w/5.4 have a bad miss and the engine surges at about 1100rpm and smooths out about 2000 rpm put on a new egr valve,egr selanoid,tps,egr control valve,pife sensor,cleaned converters out,plugs the ford garage tells me to replace a hose on the throttle body any one know what one and where its located.or any other ideas what it might be. sorry the code was po401.whipkeyjohn@yahoo.com