Can a bad head gasket Cause misfires? I have a 1999 honda civic si?

Can a bad head gasket Cause misfires? I have a 1999 honda civic si? - 1

Yes.

When is the last time you did a tune up? Plugs, wires, etc?
Sure signs of bad head gasket: check your dipstick. Is the oil on the stick creamy/milky? Pull off the oil cap. Is there a milky gunk on the bottom? Is your exhaust white and smell sweet like antifreeze? Check the coolant. Is there oil in it? After driving the car does the coolant boil? All of these are the symptoms of a bad head gasket. Misfires can be many things.