I currently have a project underway should be finished in two weeks.
I have a 1995 GMT400 SBC 5.7 TBI A couple of years ago I put a set of try-Y headers on the truck and began occasionally getting the code 32 EGR didn't bother me as it was the silly test not the actual EGR circuit.
So now I am overhauling the engine and adding a bunch of stuff.
I have ground off the air horn of the TBI unblocked the pressure adjuster and added the 1/4 inch spacer.
The intake is a matched Procomp four square dual plenum with a mid mount transadapt plate.
The Heads are pro comp 220cc 202 intake 1.65 exhaust.
The cam is a stock LT-4 roller with 1.5 rockers.
Bottom end just stock with fresh rings and bearings.
Headers are Long tube 1.75-2.5-3 single chamber race muffler 3 inch axle dump.
So absolutely no back pressure and no provision in the head or intake for EGR.

I am currently building a prototype BeagleBone Black based Fuel and trans management system so spending money on the stock computer and old style proms is not desirable.
I am an electronics engineer of sorts and have built many jettronic style ANALOG fuel injection systems in the past.

The question I have is actually pretty simple.
I know that the EGR test in the 1995 TBI vehicles takes place when coolant MPH and throttle is within parameters.
What I am looking for is the amount of MAP sensor voltage change the ECM expects.

So the TEST I understand opens the EGR looks for map change closes the EGR looks for MAP change and then reopens it.
The change in MAP voltage is what I am looking for.
Does anyone know the expected change in map voltage?
If anyone can check for me or knows off hand from prom bit banging I will make a small circuit that satisfies the ECM test and post the schematic here.
My current thought is that the solenoid signal can be used to trigger a Map sensor voltage change.