You didn't say what year, this should have 3 ignition coils on plugs and 3 wires running to the other plugs. These coils fail and will cause roughness. Also, make sure the wires are routed to the proper cylinders. I'd run drive the car, shut it off then pull plugs and look for carbon / wet with fuel.

If the plugs look clean but slightly oily, look for a injector that is not firing.

Another way to test is to start a cold engine then use a heat gun to measure temps at each exhaust port. A dead miss will be cold . ( you can feel for heat if you start with a _COLD_engine that has not run more than a minute. )