my 96 SS has had a bit of a rough idle since I bought it this spring. So far I have changed fuel filter, egr valve/solenoid, pcv valve and now have new plugs in it. It seems to jump around between 600rpm and 900rpm while stopped. Driving there are zero issues and it is not throwing the CEL. AM I just being too d#$m picky or is there another part I should check into.