2000 Hyundai Elantra P0303

Can reset code but it comes right back. Engine misses all of the time. Replaced plugs, no change. Inductive timing light will flash rapidly on cyl 1, 2, and 4 but on 3 sometimes no flash or very sporadic, plug wire measures about 2000 ohms. Reconnected throttle pos sensor and the connecter to the coil module. No change. Suspect a new coil module will fix it. What do you think? No problems with the engine running untill this happened. Ie no warnings or other unusual symptoms. Thanks Larry