EGR Flow Error, wits end.

I have a P0401 code (EGR Valve insufficient flow). I have replaced the EGR Valve, reset the codes and it came back, cleaned out the pipe going from the exhaust to the EGR, reset the codes and it came back.

Any other known causes?

2004 Pontiac Grandam 96,000 miles.

Need to take throttle body off, and clean the EGR ports. The EGR ports will get plugged will emission gunk.

Need to take throttle body off, and clean the EGR ports. The EGR ports will get plugged will emission gunk.

Will do. Thanks!

Anything else I should check into?