it revs up and down at a idle,driving down the road at a stalled speed it revs

I would recommend cleaning out the IACV and FITV valves. Vacuum leaks specially can cause a surging idle yet I found in my Honda that cleaning out both of these valves solved the problem.

Coolant level correct?

Change the egr valve and make sure your plugs are gapped correctly. Check your owners manuel for the correct gap