My boyfriend's car came up with a PO401 code. I guess that is "insufficient EGR flow detected." Has anyone experienced this code? If so, what turned out to be the problem? Was it just clogged or what?

I had a similar problem,on a 2000 v6 you need to check the ohms across the last 2 pins on the egr position sensor.The sensor is ontop of the egr valve .The resistance should not be above 4.5 ohms. my new one was 3.5 also to buy it from the dealer 35.00 .to buy it from elsewhere 100.00