Chevrolet Repair: Trouble code P0300, trouble code p0300, inductive timing light

Question
1998 Cavalier 2.2 liter auto   74K
Plugs and wire changed last summer
Trouble code P0302 came up. I changed both coils and the car ran good for 3 weeks.
Now I get code P0300(random/multiple misfire).
I hooked an inductive timing light to each plug wire. The light would flash consistently and then every once in a while it would skip a flash. This makes me think it's electrical, not gas related.
Any ideas on what to check next?
     Thanks in advance....Bob  

Answer
Hi Bob, Well if you haven't changed the plug wires I would so first. If you have then you might have a injector that isn't spraying correctly. This can be cleaned with a through the fuel rail cleaner, not a tank added cleaner.
We do this at the dealer for around $80.

Hope this helps

Mark