Rep Power: 0

Ok here it is. Bought my son a 2001 Honda Civic LX. We have changed the following and still the car will not stay on! Computer keeps saying EGR valve which it doesn't have one. Besides myself trying to get this car running, it starts - rough idle but will not stay on. Please ideas welcome.
Changed - Battery, spark plugs, ignition coil, fuel injectors, fuel injector damper (rail), fuel module, crankshaft sensor, air intake compression sensor, idle control sensor, oxygen sensors, belts.

Car starts little bit rough, knocks but doesn't stay on. We have put on computer and it gives us the message of 3 misfires which are random cylinder misfire - code P0300- cylinder #2 misfire - code P0302, cylinder #1 misfire - code P0301.

 
Rep Power: 223

What brand were the sensors?
checked timing?
It throwing an egr code may mean that someone has swapped in a later computer

 
Rep Power: 134

Did the previous owner swap out the PCM from an EGR engine and did not tell you?
Did you have a mechanic check the vehicle over before the purchase and see if any codes?

 
Rep Power: 0

This model doesn't have that EGR valve have to go with the engine block number for this particular engine.