So I plugged my brand new OBDII reader in today, fired up Pearl. (2017 Abarth) and got a P0300 "Random Cylinder Misfire" error code. No CEL lights or anything else...just that code. Other than the Record Monza exhaust, that I added a few thousand miles ago, the engine and exhaust system are bone stock, 13,800 miles. Bad plug? Bad ignition coil? Injector? Guess it's time to make a service appointment. What's the most likely cause?