2008 Dodge caliber

My car is misfiring at the # 2 cylinder and replaced a new intake manifold and spark plugs with three coil packs. I had a compression test done and its states all cylinders pass above 140 PSI, they checked the coil packs and #2 cylinder was still misfiring, #2 cylinder would get fire but would not stay on. So they checked all wiring and suggested a wiring harness or PCM to be replaced. I want to know if you may help me understand what if the diagnose is correct or not? What can I do?
2008 Dodge Caliber