low rmp idle idles rough

Truck 91 chevy k1500 z71 will start good have rmps at 1000 then drops to 200 sometimes lower put it on computer got codes 32 egr valve and code 43 esc module replaced both of those still no better so replaced ignition coil and fuel pump still no different please help

Check for vacuum leaks near the intake manifold. Check the lines going to the brake booster, the vapor canister, the PCV system, and any intake manifold vacuum diverging line. .

silicon212 mentioned the PCV system. Make sure you take a look at the rubber gasket that holds the PCV into the valve cover as well. If it's loose it will cause a vacuum leak as well and an irregular idle. Changing that on my 91 years ago cleared that stumble at idle right up.

Check for vacuum leaks near the intake manifold. Check the lines going to the brake booster, the vapor canister, the PCV system, and any intake manifold vacuum diverging line. .
TB base gasket is a common source for vacuum leaks.

Since you had a code 32, did you also check the EGR solenoid? It should hold vacuum on TBI side. How to the vacuum lines look for EGR and EGR solenoid?

//2000CAYukon