Code PO304 # 4 plug misfire

[Dcrusoe]

Hello all,

My code reader is showing a P0304 - #4 plug misfire. Ie changed spark plugs (shop tuned it and did the work) Ie checked the gap on the plug pulled the spark plug wire and can see a good spark flying from it. yet it is still misfiring.
I put a compression gage on it and getting 120 to 140 PSI. And I out of ideas. I do not want to take it to a shop untill I know what they need to do with todays prices to just start searching untill they find it.

Any pointers of what to look at next? Please!

[stomana]

check the ignition coil

[blazee]

If you're getting good spark it is probably the injector. (either clogged or not working properly) Run a bottle of injector cleaner through and see if that helps.