Yeah I've erased it and it keeps coming back

I changed the ignition coils and wires but still nothing. Then I bought original Volvo spark plugs and the misfiring stopped. I had used Champion Iridium plugs before and they were about 2 months old. I took them out and saw that there were deposits pretty far up the thread. Is this normal? Does thi...

My 2000 Volvo S40 1.9T is showing the following error codes: P0017 Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B) P0301 Cylinder 1 Misfire Detected P0302 Cylinder 2 Misfire Detected P0303 Cylinder 3 Misfire Detected P0304 Cylinder 4 Misfire Detected When I start the car and th...