I own a 99 Civic EX and got a check engine light about a month ago. It was a misfire in cylinder 2. Replacing all the sparkplugs we found that the second cylinder was cross threaded or righted too much. We got a rethread kit and fixed it. The check engine light went away but just recently it came back on. Saying cylinder 1 and 2 were now misfiring. I've put about 100 miles on it with the check engine light off so I'm not sure what this could be. Any advice?