Car stalling when driving then troubles starting again

1985 oldsmobile cutlass calais, 3.0. 6 cylinder fuel injected. I changed the spark plugs today and the stalling is still occuring but car isnt chugging like it used too. Could it be be the egr causing it to stall then not start up? What should I try first? Egr came up on the diagnostic test. How do I clean the egr or check to see if it is the problem? Please help with any imformation on this problem.