help what to do cylinder misfire 1, 2, 3, & 4 2001 honda civic ex
could it be because since i brought the car i only put 93 gas in it 60,000
miles later i put 89 in it by mistake could that have caused the misfire or its just time for a coil change. oh yea i changed my plugs and the misfire is still coming up on the computer i don't know what to do

help me please