Defective spark plug or plug wire, burnt valve, blown head gasket, fuel injector problem, or broken piston ring.
The most common reason for a misfire is the ignition coil that is connected to the sparkplug on top of the problem cylinder.
( no ) The 1.9 liter four cylinder engine in a 1999 Saturn S series has a timing CHAIN
Most likely a bad ignition oil. Each cylinder has its own coil mounted at the top of the spark plug
It could just be a bad spark plug wire or the spark plugs need changing.
P0304 : cylinder number 4 misfire.
# 5 engine cylinder - misfire detected
a bad wire or a bad coil to cylinder 5.
Bad spark plug, plug wire. I hade that problem it was a cracked head "Expensive"
Spark plug, wire, coil, low compression, fuel injector, intake leak, etc.
Oil capacity for your 1999 Saturn DOHC 4-cylinder motor is 4 Quarts of oil
Yes.
P0306 Cylinder 6 Misfire Detected