1. What’s the miles on the car? 2. You’re seeing misfire codes? What specifically? Since what miles? 3. You cleaned the complete EGR system, including the intake manifold, and at what miles did you do that?
And we know this how? Misfiring on all cylinders? Coil conditions plug conditions? For everything to be missing all at once on all four sounds like an electrical problem or something along those lines or one hell of an engine failure