Q: Intermittent cylinder misfiring on a '98 Grand Marquis

What you should do, if you don’t have the equipment and you don’t understand it is to call a professional to take a look into your misfiring problem for you. Mechanics, like those from YourMechanic and myself, we’ve been doing it for a long time. We’ll put a scan tool on it and check live mode six data, and all stored codes.

You’ll get all kind of information like where misfires are coming from and how often. Those machines are so good these days that I could plug something in it, and it will tell me things like: cylinder number six has misfired 6081 times, and number two has only misfired five times, and number three hasn’t misfired at all. It stores everything. So, start there. There’s no sense guessing.