Daughters 02 honda civic has been running poorly. Lots of missing. Codes a random misfire in all 4. Trip to the dealer, 2 ignition coils, 2 seperate diag. checks later somebody finally pulls a plug and declares someone ran deisel in it.To me, seems they should have started at the plugs. I think it is not deisel because she says the car never smoked. What else could be going on that would leave an oily deposit and foul the plugs? The car only has 44,000 miles on it and ran fine when she purchased it several months ago. Must point out it was a Katrina car that she bought "as is" after being told it only flooded to the floor board. Waterline in trunk and door frames says flooded to the windows. Thanks for any help.