Bro, I am not an expert in EGR and certainly not in Passo, but I will share what I know. EGR means exhaust gas re-circulation which is a system designed to channel back some of your exhaust back into your air intake. It's very common to have carbon build-up in a car's EGR system which can clog it, sometimes to such an extent that relevant parts need replacement.
In my Lancer 2005, it was a MECHANICAL valve which I got cleaned as it was full of carbon. There was absolutely no code or nothing wrong with the car, I just did it for the heck of it.
Now, I have Accord CL9 which does not have an EGR valve as such, but has a series of alleys and channels in its intake which perform the EGR job. I also got my intake removed and got the EGR 'plate' cleaned, again just for the heck of it - there was nothing wrong with the car.
