If your EGR valve is faulty a blanking plate will fix the problem completely. For a couple of bucks and a very small amount of time you could do a mod that most of us do anyway and perhaps resolve the problem!
The lack of smoke would imply a fuel delivery problem though. If it smoked like mad it could be EGR - which dampens combustion by replacing part of the air with exhaust gas - but if there's no smoke, it's either fuelled properly or underfuelled.
Underfuelling could be caused by several things. One member here had stuff lying in the tank and blocking the fuel pickup. Another had a long range tank fitted and when the original tank was returned to its original position, the fuel line was crushed above it (this caused problems with high-end performance).
More likely though, it might be the suction control valve. Had a few reports of "faulty" SCVs causing issues with a "limp mode" kind of behaviour. I went for a drive with one of our members here who demonstrated the most common behaviour - drive along at around 80km/h and plant the foot to the floor = instant limp mode, but gentle acceleration and it was fine. Had to turn the car off and back on again to fix it.
If it IS your SCV it's not easy to tell, but you can remove it, clean it and reinstall it - had a couple of reports where just cleaning the SCV resolved the issue (saves you spending $240 too).
