Run a compression test and see how #3 stacks up. Possible burnt valve or blown head gasket.
Check your plug again on cylinder 3. Sometimes you can crack the plug installing it.
You also can check cylinder 3 injector.
Code P0304: Misfire at cylinder 4 detected.
A misfire has been detected in engine cylinder # 4
# 5 engine cylinder - misfire detected
the code p0304 is cylinder 4 misfire detected
It means that more than one cylinder has a misfire history. PO301 would be cylinder number 1 misfire. PO302 would be number 3 cylinder misfire.
Try replacing the plugs and wires
Misfire on more than one cylinder. Start by replacing your plugs and plug wires. If that does not solve the problem, run a compression test to determine if you have a burnt valve.
po300-Random/multiple cylinder misfire detected. po303-Cylinder no. 3 misfire detected. po306-cylinder no. 6 misfire detected po300-Random/multiple cylinder misfire detected. po303-Cylinder no. 3 misfire detected. po306-cylinder no. 6 misfire detected
How is your coil pack ?
P0300 - Random Misfire . P0300 indicates multiple cylinders are misfiring or the PCM cannot identify which cylinder is misfiring .
Cylinder #4 misfireCylinder #4 misfire
Cylinder #2 misfire.Cylinder #2 misfire.