I have removed and either replaced or bench tested every component on my EGR systems. Including taking my intake manifold out and cleansing all carbon out of it and the EGR port and removing and testing my VSV. Someone told me that it could be the catalytic converter, and at $500+ just for the part I want to be absolutely certain that I didnt miss anything. I
Can my Catalytic Converter cause "Insufficient Flow" code P0401? on 2001 Toyota Camry
by memichaelt in Woodstock, GA on September 27, 2010
ANSWER by Bret Bodas , September 27, 2010
Here's some info that may help: http://repairpal.com/OBD-II-Code-P0401-Toyota Good Luck!