Did you also clean the tube between the exhaust manifold and the EGR valve?
The tube, especially where it connects to the exhaust manifold, may be
clogged and you will get the same trouble code.

If the check engine light illuminates again, then you should check the
trouble codes again because it is possible that the same or a different
fault is causing the light to come on.

If you get the same trouble code (P0401), then the diagnostic process is
pretty much the same.  A replacement EGR valve may or may not solve the
problem because the EGR valve may or may not be the cause of the check
engine light.  If you are willing to replace a part even though the parts
replacement may not solve the problem, then you can replace the EGR valve.

Today I removed the EGR valve, there was some carbon, but not much.  There
was only a think layer of carbon.  I cleaned it up.  I did reset the light,
and now waiting to see if the light comes back.  If the light comes back,
does it necessarily mean that a new EGR valve will solve it?  Thanks.

How many miles are on the car?  With the engine idling, apply vacuum to the
EGR valve and see if the engine starts to idle roughly or start to die.  If
that happens, check the EGR position sensor.  If the engine does not start
to die, check the EGR tube for blockage.  Most likely, the EGR tube is
blocked with carbon buildup.  If that is the case, you can try to dig out
some of the carbon or replace the EGR valve and tube.

Hello,

My Camry '97 just failed inspection.  It is code P0401. 'Exhaust Gas
Recirculation Flow Insufficient Detected.'  Would you please give me your
recommendations.

Thanks,
Talal Itani