MISFIRING ON CYLINDER 1 VW POLO 1.4 3CYLINDER

I have changed a few cylinder heads under warranty for this type of problem. The exhaust valve guides wear, this causes the exhaust valve to seat badly, giving low compression. if one cylinder compresion reading is more than about 50 psi below the others, then this warrants head removal. It is quite a job, due to the fact that the camshft id chain driven. If you are up for it then once the head is removed, poor liquid into the exhaust ports and see if it leaks out through any of the exhaust valves.

there maybe something wrong in your engine block thats why its misfiring on 1. have it check by professionals.