96 camry cel

[brokenrado]

ive got a 96 camry 4cyl with code p0401 (insufficient egr flow)

i put vacuum on the egr and the car started to stumble. so it should be working good

i tested the resistance across the vsv and it was good. and on the advice of the diag tech at work i replaced the modulator and the vsv. well the cel came back on today. anybody have any advice

[hzt30]

You can do a search, there are several threads on this forum regarding the P0401 code.

You could have blocked EGR ports, even though applying vacuum caused the engine to stumble.
There is a port that goes to the bottom of the modulator via a hose. This port could be blocked or the hose could be leaking. This hose applies back pressure to the modulator which allows it to operate.
Try removing the EGR valve and clean out the ports, if blocked.

If you have a service manual, it explains how to test the EGR system.