How do you get the check engine light to go off of 1998 Chevy lumina after you replaced EGR valve two times Code still reads P0401?

Answer 1

I have come across this same problem many times with Ford & Isuzu, & it is worth a shot on your Lumina. You will need to take the EGR valve off & check the port that goes to the intake & make sure that it is clean, many times these ports are so small that they stop up with carbon from the exhaust. If it is stopped up you will have to clean it out maybe with a small piece of wire, just do not let the wire fall into the intake, or if it is really bad you will have to remove the intake to gain better access to this port. Once you have the port unstopped you can start the engine with the valve still off & make sure that you have vacuum on this port & make sure you have exhaust coming out of the other port. This has worked for me on several cars & has kept the light off & no more P0401. I hope that this helps. God Bless

I seem to recall that, in some cases, there is a recalibration sequence for the EGR valve, though I agree that verifying the integrity of the manifold ports should come first. Also, check the wiring, and make sure the EGR position readback on the scantool is working.