Where is number 4 spark plug located on a 2004 Mitzubishi galant

6 cylinder

Middle cylinder at the front of the vehicle.

Thank you so much, you saved me a lot of work. I thought I would have had to get under the engine

You are lucky it was not one of the back cylinders. Good luck with it.

Faulty plug? Maybe. Bad wire? Maybe. You can take out the plug, reattach the wire. Then check for spark. May have a bad coil pack. Next check cylinder compression. If that's all good , may be fuel injector. Check for pulse. I use noid lights.