So I've had a 2003 Honda Civic EX with the V-Tech engine to be specific and recently I've been getting son codes on my cylinders misfiring first I got a code on cylinder 1 so we go in and swap coils from 1 to 2 to see if it was the coil that was the problem. Ok now cylinder 2 is misfiring so we put a new coil and it was still misfiring so I swapped the new coil from 2 to 4 and still had problems with 2 so I threw pricy fuel injector cleaner in and now I've got codes on 1,2, and 3. My question is is it the fuel injecter cleaner cleaning out my cylinders so it's setting off all these codes or is it me driving it damaging my car? Sorry for the long explanation but I wanted to be through.

 

Fuel injector cleaner will usually cause misfires.

Are you clearing the codes between tests?