A Few Fuel Injection Questions

1999 Misfire Codes P0300 P0302
Got a OBD 11 tester and i have a P0300 and P0302, or a misfire in #2 cylinder. Rechecked plug and wire, replaced wire, replaced coil for that cylinder. Sounds a bit better but still idles like a misfire, tester shows a misfire that is the only bad cylinder whats next, resistance?

2002 Grand Am SES p0300 p0404. EGR Catalytic Converter PCM
The thing surges and sputters, and just runs bad. Has no power to pull itself up hills. If I drive it like there's an egg under the gas pedal. I can run 80 mph on flat ground easily.

Check Engine Light Code P0300 on 2005 3800 V6
My 2005 Pontiac Grand Prix has a check engine light on. It also hesitates a little bit. Had codes scanned and came with misfire intermittent on a few different cylinders. We did a tune up.

Change Spark Plugs on 2.2l Oldsmobile Engine
How to change the spark plugs but don't have any idea on how to tackle the coil over plug system. Could you give me some tips.

My 2003 Buick Rendezvous Sputters Service Engine Soon
At idle and at very low speeds when we're first taking off, backing up or slowing down truck starts to sputter and jump and feels like it wants to cut off. At normal speeds, the car runs perfect.