You can move the coil packs around and see if the code follows the coil pack. That' if you get a code for say, missfire in #2. Move it to #4 and see if the code follows it.
How many miles on the car ?
How long has it been on tune ?
174,000+ miles, 5/20/12 new ej257 short block, 8/20/11 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. Also CHECK YOUR OIL, these cars use it.