EGR Problem

[Purple]

My '95 2.2L Odyssey has the code 12 showing up for EGR problem.
This only happens when the engine is started from cold and once its driven a few hundred meters the check engine light will come on.
Any starts after the engine is warmed up and the light stays off.

I have cleaned the EGR ports by removing the plate on the manifold. There was a lot of carbon to clean out yet none of the ports were actually blocked. However the light still comes on as before.

What should I check next ?

[ECU-MAN]

http://www.ozhonda.com/forum/showthr...33#post1196533

[Purple]

http://www.ozhonda.com/forum/showthr...33#post1196533

Ok thanks for that.
Just trying to establish the fault relationship to when the engine is cold. By doing some of these tests, the engine will warm up and the fault will probably disappear and make it very difficult to find the culprit.