Hi. This car keeps turning on the CEL and giving me a P0303 code, which I know is a misfire on #3 cylinder. I have swapped coil packs, injectors, and plugs between cylinders and nothing has changed. It is hard to start after it has been sitting for a while, but when it starts, it runs great, and if you try to restart it after it initially starts, it starts fine then also. Someone suggested the fuel pressure regulator, which kinda makes sense, but why would that cause a misfire code always on #3? Any ideas? Thanx in advance.