2002 Mazda 626 V6 egr code p0400 where is it and how to clean up?

The EGR is on the back half of the motor. pull the throttlebody off and you can get to it. There is one electrical connector and 2 fuel lines, also an exhaust line. everything will come off easily, except for the exhaust line. the part will cost between $250 and $500. dont clean it up, just replace it. its a lot of work to do to just find out that its really bad.