This video is for the repair of a p0401 after an egr valve has been replaced and the code comes back p0401 low flow or efficiency.

also the torque spec for the throttle body is 90 inch lbs. not 192 in lbs

if you get the code p0401 before replacing the egr valve clean the egr ports. you will notice a bit of slag in the egr passages. they were plugged. just needs a good cleaning. If the egr valve holds vacuum then the ports are plugged. enjoy the video