Beginning yesterday my car began to run rough. Today the CEL comes on with code p0302 for a misfire in cylinder 2. Tonight I changed that plug and start it up and I now have a pending code for cylinder 3 misfiring. I have yet to drive it, but it definitely sounds and feels much better than earlier. I plan on changing the rest of the plugs tomorrow. My question is, should I expect there to be something more wrong. I find it odd that changing the one plug made the code jump to different cylinder. The only thing I have done recently to the car is buy gas at a brand new gas station, the problems seemed to start the day after. Any help is much appreciated.