2003 Ford Expedition Q&A
2003 Ford Expedition Question: random misfire
Check your fuel trim numbers. The Diagnostic read was not really a full one. You need to check the Fuel Trim and other data values. There is much., much more going on than just checking for the presence of codes, and if there is a code, you need to study the context of the problem. You may have a LEAN misfire which will set a P0300 which is a random misfire. This can be caused by small vacuum leaks, worn but not yet failed sensors etc This is a common code on your engine, but there are several things that can cause it, so with out a real scan of your system, you and I are still not sure of the cause of the problem. It is best to have an Emissions expert look at this type of Code. I do Emissions work in California, and I see this type of stuff every week. A person who does not really do emissions work will be puzzled by this. Ask for a shop with a really good Emissions Diagnostic Tech. - dandd
...all wires replaced, & coil packs replaced. now, instead of a specific misfire code, it pops up random misfire. getting a new "crank something" done today. if that doesn't work, what next? truck loses powe...
Scanner showed #5 misfire. Never have had tune-up with over 160K so had plugs, coil packs, belt & fuel filter changed. Runs rough randomly at least once a day. What could cause this?
We have a problem with our car running rough. Sometimes it drives fine, and sometimes it drives really rough. We have replaced the EGR valve and two out of the eight coils. (Had a code before and...