Hi guys new to the site and having trouble I have a 2003 expy 4.6 with 144,*** it's also 4x4. Well the problem I'm having is recently it started jumping almost seems like cutting in and out on acceleration idles fine just when you give it gas. I have no cel on but I kinda got on it and the cel flashed on and off so been reading on the net and it seems like its a misfire but the cel is not on so I don't know what one is bad are the codes stored in the computer so if I hooked up a scanner would it tell me I'm stumped and annoyed also how hard is it to change coil pack and plugs