po401 insuficient egr flow, 97 lumina

[frank b]

My 97 lumina 3.1 has had the po401 code for a while now. I've cleaned the passages, and even replaced the egr valve with an AC Delco unit. Each time I reset or erased the code but a short drive and it's back.

Any ideas????

 

[slick]

When you cleaned it, did you pull the throttle body off as well to help with the cleaning process?

[cubsfan24]

I had this same problem a couple weeks ago. I followed the advice in this link: http://www.w-body.com/forum/index.php?topic=68562.0

 

I pushed a rod through the passage way from the EGR valve to the intake and that fixed the problem. As slick said you have to take the throttle body off to clean it better.

 

 

[89SupremeCutty]

i just had this problem last week. i took it to a shop to have the yearly nys inspection and that was one of the codes that was on. it turned out to be a blown lower intake manifold gasket. cleaning it might help.