Disable the EGR Valve
If you have checked the EGR valve and found a vacuum leek, and the all other vacuum is in order. Or your car is slow to the start and smokes black until turbo boosts. Then proceed to the following steps. If your vacuum is in order and the engine runs fine don't disable it.
1. Locate and Unplug the vacuum line to the EGR and block hose ( anything solid , no screws )
2. Loosen 10mm locking nut on EGR
3. Turn in flathead screw until somewhat hand tight to keep valve closed under boost.
4. Start car and drive ensuring proper shifting and alleviation of smoke or poor performance.
NOTE: Take note the engine normal operating temp before and after changes, it should lower the temp by 5deg C.