03 ls v8 egr code p403

[impala_man2003]

This code has been haunting me for a while I changed the egr valve and am still getting the same code. I am preformed all the voltage and vaccume test and still get p403 any suggestion I m stuck at this point

 

[joegr]

P403 is not a valid code. Do you mean P0403?

Did you replace it with a new valve or a used one?

It's an electrical issue. Either the new/used valve assembly is bad, or you have a broken or shorted wire somewhere between the valve and the PCM. The connectors should be suspect too.