2003 Avalanche
I have an occasional misfire ( when RPM'* are coming down and around 1000-1300 then occasionally at a red light and also under a load) and not sure where it is coming from. I just replaced plugs and wires and it is still there. It rarely throws a light so there'* no code to to pull. Aside from starting to replace coils... any other ideas or help and suggestions to diag where it is coming from?

thanks!