P1491 Honda - odyssey

Question

I have cleaned all the ports for the EGR valve P0401 code and now get a P1491 code and a P0401 pending code, never a P0401 code without the pending. In addition to cleaning all the ports I replaced the EGR valve. Any ideas on what could be causing the continued P1491?

Answer 1

P1491 EGR valve insufficient lift

P0401 EGR insuffiecent flow

Was the EGR ports plugged? You may have to do more in some instances the intake manifold has to be  removed just to get the port really cleared. Put the old EGR valve back in its place clear the code , test drive if you get P0401 , remove the intake to get all the way through the passage of the EGR passage.