Thanks for your response. I'm having a cylinder 3 misfire. I've tried everything possible to fix it. I figured I might try the seafoam thinking maybe carbon build-up on the.piston or valves.
Not the way to go about this. First to fix an issue like you describe (carbon buildup) you would have to use seafoam sprayed through the intake or sucked into a vacuum line, not poured into the crankcase. Second, if the cylinder is not firing the seafoam wouldn't really do anything because it relies on it being turned to steam by the cylinders heat to bust up the carbon. Seafoam in the oil might free up a stuck lifter that could cause a miss, but your engine doesn't have lifters.
You should confirm the problem first by going through the basics, check spark on #3, check compression wet and dry, and test the injector.
I highly doubt seafoam or any chemical is gonna fix or diagnose the issue here. I've never found any chemicals or additives that can work miracles. Sure some are great for maintenance but they never really "fix" anything once it's broke.