95 Chevy 454

Check the voltage on the Blue wire to the knock sensor. Open circuit voltage with the knock sensor disconnected should be 5.0 volts. With the knock sensor connected, voltage should drop to 2.5 volts. Check for shorts to ground, faulty connections, broken or frayed wiring. If these are OK, replace the knock sensor
 
1. Monitor the Throttle Position Sensor (TPS) voltage reading on the scanner and see if it is erratic.

2. Backprobe a voltmeter at the Blue TPS signal wire at the Powertrain Control Module (PCM). See if it shows the same as the scanner, or if it reads a steady voltage.

3. Check the 5-volt reference on the Gray wire at the TPS for dropping out.

4. Voltage drop the Black wire from the TPS and make sure it is less than 0.05 volts.

5. If the voltage is steady on the Blue wire, but the voltage and throttle angle is erratic on the scanner, replace the PCM

The blue wire to the TPS and knock sensor are tied together and a brake in that wire could cause a lot of your problems
 
ESC is a ~3"x3" flat little module on a bracket attached to the intake manifold.
EGR - you could have one of 2 types. 1 is standard old Chevy style. other is a stepper motor style (aka more $) Looks like a small motor bolted to the intake. The wrong one can cause surging and knock due to too much exhaust being passed in.
IAC attached to the TBI unit. Would be more of an idleing issue..
Check the wire and the connector on the knock sensor, the big block exhaust runs hot (as I'm sure you know) and it can bake those wires.

Also make sure the distributor is set right. Mine was off by 2deg that can cause spark knock. Make sure you pull the connector to set the timing. mine was still wrapped up into the harness with black tape. 95s can be either on the fire wall or like mine behind the glove box, look for a bump in the harness and poke around.
 
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