added cam idle issues 350 chevrolet

I have a 1989 V1500 Jimmy, has a 5.7 non vortec head engine. added the comp cams 12-304-4 cam using my tbi set up. The only issue is when idleing the idle drops down and causes a stall or if I pull up to a light to stop it will stall, The engine light comes on showing egr issue, but egr is brand new……