I have a 2000 Navigator with probably about 108K plus miles on it. Back in June I went to some small shop and I got a tune up done on my car. They did it, and it ran like poop, and later realized they put the wrong parts in (it wasn't for a 2000 Navigator). They supposedly fixed it. Now, a few months later, I have had 2 incidents where the " Service Enginer Soon" light comes on. The first time, there was a cylinder 3 misfire, so I took it to a dealership and paid almost $300 to get the coil and spark plug replaced. Now #1 is misfiring.I wanted to know, should I go back to the guy who did the tune up, a friend said this should not be happening since I just got a tune up done.
Coil pack failure is very likely the case and those were probably not changed when the tune up was done (you should see if any were on your repair slip). If they were then it should be warrantied, if not as I've said another coil pack failing is not uncommon.