P0300 random misfire.

[Jaded_Crown]

I've recently had my car serviced and it now comes up with a P0300, the service included both a timing belt and heated O2 sensor, I checked the spark plugs and they are fine. I would appreciate some help identifying the cause, thanks.

[Eg.h2o]

Could be the plug wires, the coil, or oil in the spark plug tubes depending on the year.

[Jaded_Crown]

it's a 2006 I checked plugs and tubes, haven't tested the coil yet. I had an aftermarket pod filter on the car, which I reverted to standard. idles better with original airbox, but issue still persists.