weak cylinder 1994 cutlass

1994 cutlass cranksaft sensor cicuit code im in the process of figuring out it its the senor the wires or the computer, car starts good runs ok but idles terrible but never cut off i had it checked with a bear 400 engine analyzer and it found that my clinder number three was very weak very low compared to the others , i was told it could carbon build up is it any quck fix for this or anything that would atleast help or would the only way be to replace the piston or have it machined could it be coil pack ? also the codes in the computer stated bad egr solenoids, crank sensor circuit , idle position please give me your opionions thanks