99 TJ - this all started last week. Driving down the highway I noticed a bad miss and my check engine light flashed. This continued intermittently until I stopped although the miss and check engine light flash did decrease significantly as I had less of a load on the motor. I drove home and took it easy, stayed off-highway, and it happened a few times more. Over the weekend I changed plugs, rotor, cap, and coil. Still happening. Particularly under more of a load and more frequently as the Jeep is up to temp. I am hoping its not a head gasket. No apparent water in oil or oil in water. Any guidance?