When i idle the car in park with the a/c on level 1 i get a strong smell of gas and exhaust

Have changed coils three times, each time I change the coil, the engine become very hot and burn the coil, I recently changed the head gasket but still it over heat, I took off the ECU for repair, before then it was cylinder 1 that misfires but after the repairs it shifted to cylinder 4 now, it gives a very rough idle and popping exhaust sound, can smell fuel at the exhaust when engine starts cold... Kindly help me am very confused here.