The coils are wired in series, so cylinders 1 & 4 or connected together, as well as 3 & 2. So Pete's right, you cant just disconnect one coil to locate which cylinder is misfiring. I've had a lot of problems with injectors on Clio's, so that may well be a good place to start looking on this one. Not always easy to detect electrically as they appear to fail mechanically, hence the ECU wont pick it up as a circuit fault.