So my check engine light on my 2004 RSX type S came on, i got it checked out and it said "misfire cylinder 1". At autozone they said its usually bad sparkplugs. So I just replaced alll the spark plugs. Next day, check engine light is back on, now not just cylinder 1, but cylinder 3 as well, and also random misfire.

Someone said possibly dirty injectors, so i ran a bottle of lucas fuel injector cleaner through it and the light is still on..

What causes these codes to show up and what do I have to do to get rid of it?