I ran it with an OBD Code reader permanently attached for two months. Which always gave the same code when the EML came on. 401 Insufficient flow EGR .
I phoned a 'Independent' Honda Specialist , who advised me that, the EGR passages that are behind the Inlet manifold gasket will be blocked. He quoted £180 , to do the job ?
So , yesterday, out with the socket sets, and thirty minutes later the inlet manifold was off.
There is a steel gasket behind the manifold , which once removed reveals the passages that link the Egr valve to the exhaust .
Wow , these were full of oily thick carbon , with only a very tiny passage remaining for gas to flow through.
A flat bladed screw driver , and a can of egr cleaner, removed masses of baked in carbon.
No new gaskets were required , and an hour later , it was like having a new engine fitted.
NO EML , NO Juddering , 40 Plus mpg showing on the dash. And it didnt cost a penny.
This is after buying and fitting;
8 PLUGS
2 LAMDA SENSORS.
1 EGR VALVE
All advised by garage mechanics , after OBD Assessment's.
So, from my experience , if you get a 401 code ,'Insufficient EGR Flow'.
1, clean the EGR Valve.
2, Remove the inlet manifold, and clean the passages , as described above.
Likely Cost , 1tin of Hots EGR cleaner Spray £5.00.
I hope this helps someone.