I have a 2000 SLE Bonne and after i went over a puddle under lots of rain it started being slugish and had poor acceleration. The "SERVICE ENGINE SOON" light came on and i went to Autozone to get it read and it came out P0300 which is according to them multiple engine missfires. I tried replacing the spark plugs and wires and no good, what could be the next step or the cause for this problem? The car used to run fine and after the soaking in a puddle it went haywire on me.