Hey guys, i am hoping someone on here can help me. I am sure this has been beat to death, but i am at a loss. My son just bought his first car and it is a 1999 Kia sephia 1.8l. We drove it home, everything is fine, i put my scan tool on it and it shows no codes and has a green readiness light. So we drive down to get the emission and safety done and when the tech gets into the car it has a check engine light on for misfire in cylinder #4, great, so we fail, so we reset the code and start driving to get the emissions to cycle and the engine light comes on again, long story short, we have replaced the plugs, swapped the coil packs, swapped injectors, changed the fuel filter, sprayed starting fluid around intake to check for leaks, checked compression it is about 155 lbs, I dont know what else to try, My son got a job earned enough money to get this car and now its not going as planned, i want this to be a good experience for him, does anyone have any other ideas to try or has fixed this issue on one of these cars. Any help is greatly appreciated, Bruce!!