I have a 2000 gtp. Car came to me needing an alternator and had a p0303 cylinder 3 ignition misfire. the car had a steady miss but otherwise ran ok. I replaced the alternator and replaced the plugs and wires. Now when it first starts up it runs fine, but after about 10 seconds it loses a few cylinders and they come and go, but the car has no power at all, as if in limp mode. i am clueless as to what it could be, all connections are good. any help appreciated!!