Blanking plate for EGR valve. Does it work wonders

[Holywood]

Hi I have a 1997 A4 1.9 Tdi Quattro, just got it four wheel drive dynamometered on a rolling road yesterday with pleasant results. Instead of the specified 110 bhp and 235 Nm torque, my un-tuned motor has 130 bhp and 300 Nm torque. I am thinking of getting the car chipped or tuned now after that. While I was there I was told that one of the best things I could do for my Tdi in to blank off the pipe for the EGR, by replacing the metal plate with the hole inside it, with a blank flat plate. This will stop all the exhaust crap emissions going back through the engine, dirtying it and creating no good for it. It will however be worse for a tree or two in the environment. I was told this is a very easy way of getting 2-3 mpg better, an saving my engine for longer life etc and reduce the corrosive fumes that eat exhaust pipes. Any body ever done this, do you need to create an alternative exit for the exhaust gas if you blank off it's normal route through the EGR valve etc? Where can I get a piece of blanking plate from, or should I just get a local metal worker to cut one for me?
I'd appreciate your views on this.
Regards

 

[ImolaS4]

I don't know if this applies to Tdi engines, but the problem with this mod on other engines will be that the O2 sensor will be giving false readings to the ecu and the data the ecu uses will be compromised. The engine may get a lean mix; at the least, a CEL will come up.