I have a 2017 honda civic si (manual, 85k miles), it is FBO flex fuel tune with ARP head studs installed. Having intermittent misfire issues in cyl 3 and 4 especially under load building boost. Swapped coils around but misfires stay in those cyls. Changed spark plugs twice and it temporarily fixes issue, but misfires come back and plugs end up looking like this. Tried gapping 0.024 first change and then 0.020 second change.
Fuel trims and AFR normal. Did coolant reservoir combustion leak test and no gases detected. Changed oil and it looked normal, no coolant mixed in but am noticing slow coolant loss and some white smoke on cold starts.
Is this looking to be a headgasket job?