I am getting an engine code P0303 ( cylander 3 misfire) and P0158 (o2 circuit high voltage)

Is this do to a bad coil - if so, how do you check the coil since you cannot switch coils around since they are hard wired to the whole coil pack. Is their another cylander that fires at the same time that you can switch the wire to to check. ( perhaps the other side of that individual coil)

or is it a

Bad Injector - how do you remove and check to see if it is bad.

please advise?????????????????????????

 

Help Please