206 missfire problem

Good day/afternoon everyone. I'm New to this forum n would like some advice n help pls. I have a 206 which was driving fine after an engine wash. Drove approximately 50km to a mall n back. Once back home it started to missfire like crazy. Doesn't want to idle either. Engine sounds rough and has a hectic missfire and wouldn't rev up properly.I did a just the accelerator cable to get the car idling then I've removed the number 4 injector plug (gearbox end) and the engine seemed to idle much better n quieter...removed the others then engine would wanna stall...removed the number one injector plug and it idles even better just that now after removing the number 1 & 4 injector plugs its only running 2 cylinders. If I put back the number 1 & 4 injector the idle tends to drop a bit then the misfiring and rough idling starts again...on a low rev the engine is very noisy. Is there anything else I could do or try to resolve the problem or does anyone pehaps know what could be the problem. Any help would be appropriated. Tx kishaan