2002 Kia Sedona #6 cylinder misfire

My 2002 Kia Sedona will not pass emissions. First,
they said #1 and #2 o2 sensors, gas cap and # 6 cylinder misfire. I replaced the sensors and gas cap and the gas cap and the bank one sensor passed. The bank 2 sensor still failed and the #6 cylinder misfire still shows. I took it to a Kia dealership and they did compression test and told me it was either a blown headgasket or cracked head, not for sure. I
need some advice, this van is driving me crazy.