Need help code po400

i have a 95 maxima with 200600 miles on i keep getting the code p0400 (EGR Flow mailfunction) i cleaned the valve it self, then i reset the ecu, drove close to 500 miles, and the check engine light stil off so i thought that is it i got it, but tonight was leaving work the light came on i checked the the ecu and here i get the same code p0400 plus p0136 (o2 sensor ) bank1 sensor 2 which is the sensor gose in the cat converter.

need help with this please

thank you

for p0400 you are going to have to remove the intake manifold and clean all the egr passages. for p0136 you need to replace the sensor