Q: Cylinder 3 misfire

The "suspect" coil should have been tested prior to replacement; there might not have been anything wrong with it or the terminals might simply have needed to be cleaned (sometimes the terminals will get rusty or corroded). The other coils are irrelevant to the issue in cylinder No. 3. Among the causes of individual cylinder misfiring are faulty spark plugs, low compression, damage or excessive wear of spark plug wires and/or coils, faulty fuel injector, clogged EGR valves or tubes, burned valves, improper ignition timing, vacuum leaks, leaking head gasket, faulty camshaft sensor, faulty crankshaft sensor, faulty mass air flow sensor, faulty oxygen sensor, faulty throttle position sensor, faulty catalytic converter, and others. If you want the cause in your case pinpointed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a misfiring diagnostic and the responding certified mechanic will get this diagnosed and resolved for you promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic.