I have B16A engine. My modifications so far are: intake, header, exhaust, MSD SCI ignition, crane cams PS91 coil, Spoon sport sparkplug cable, fuel pressure set at 4.2 kg/cm2. I used denso iridium IK20, the gap I set it at .043 (factory setting). My question is after just around 15 miles I used the car and I checked at the sparkplug and the sparkplug become black on the sparkplug ring. Is it normal or I running rich. I did reset the ECU but it doesn’t solve the problem. Any suggestion? Thanks.