Thanks Jacekowski, some nice figures there.
As for 'if your car is running well', just read the forum about the number of issues with EGR's and DPF's!
I have read most of the forum over the 3 years I've been a member, the issues with EGRs and DPFs are always raised as a result of a car 'Not' running well.
As for the EGR, the same fuel goes into the cylinders, but there is less oxygen sothe engine runs cooler (which reduces NOX production), but this also means that less energy is produced for the same amount of fuel (i.e worse mpg).
But the EGR valve is designed to close under acceleration and cruising at a constant speed (including tickover) , and open when coasting and decelerating (I know this is a generalisation and there are many times when this might not specifically be true, but the majority of the time this is the case) So a properly working EGR will not have a huge impact on fuel economy or performance.
Yes it will allow the horrible build up of crap throughout the inlet system, but we don't know if this has been addressed by a previous owner.
Further more, if you take your MAP sensor out (it's just next to the EGR), it'll look like this:
Now tell me that your engine will not run worse as a result if your sensors (which adjust the fuelling and timing), the swirl flaps, the valves, and the manifold is coated similarly?!
Not going to dispute that, but The OP's
'159 1.9 (2008) with 185.000KM on clock, and i dont have any problems right now'
could well have been company owned and have a comprehensive service history which includes recent cleaning of the inlet system (I would guess at least 1 cambelt change, but there could well have been 2 and that could also have included a new inlet manifold)
I'm starting to guess now which isn't really a help to anyone, but there is the possibility that this car has had a lot of work done in it through it's life to keep it running right and without knowledge of that we can't just assume that it's a poor running clogged up heap. It could be in excellent condition and running well because it's always been looked after, in which case DPF removal and EGR blocking might not make such a big difference.