autozone pluged into car, and it said #7 cylinder is misfiring. on 2007 Mercury Mountaineer

check engine light is on. Called dealer, they went right to the coil. then they said 4-7 hundred dollars. Autozone code was P0307, it read #7 misfire, spark plug, coil, Vacuum leak, injector fault, high or low fuel pressure. i had work done on a 2004 escape (coil) it ran alot ruffer then my mountaineer, I was going to change the plugs until I saw you had too take have the engine apart to do it.

by in Wayne, MI on July 17, 2013
2 answers 3 comments
ANSWER by on July 17, 2013
working on 2007 explorer sport trac with 4.6 right now. has 98k miles on it. has #2 misfire on it. needs #2 coil and plugs. if you have 100k or more miles and have not changed plugs, its time for tuneup. take it to a shop that deals with doing these as the plugs break when taking out. there is a tool to remove the broken plugs without any problem. takes about 30 minutes to remove each broken plug.
COMMENT by on July 18, 2013
Thanks for the help. How long or how much damage to the engine, if i wait a week or two, then get it fix.
COMMENT by on July 18, 2013
have had people drive a little while with miss. don't plan long trip as damage to catalytic converter will occur. then becomes an expensive repair.
ANSWER by on July 18, 2013
There could be many reasons cylinder #7 miss fires. The list you got from the parts store is a great start. The plugs do break on this motor so make sure you take it to a quality repair shop that can handle them if they break. If you want us to check this out please call 313-562-7022 or schedule an appointment on line at StansGarage.net. I am sure we can diagnose it and give you the answer you need. Larry
COMMENT by on July 19, 2013
thanks for the offer, I just dropped it of at bell tire in westland, I hope it is just a plug and not the coil, I did read that it takes about two hours to get a plug out. alot different from the old cars.