Start at the ALDA and locate the banjo bolt usually located on the driver's side. Follow the plastic tube that runs from the banjo bolt to the firewall. There you will find that the tube from the ALDA junctions with a small cylinder attached to the firewall (this little cylinder is the backup in case the wastegate fails and too much boost is detected; the excess pressure bleeds right out of the top of the unit = overboost protection). Remove the banjo bolt from the ALDA and disconnect the tube from the overboost protector. Blow the tube and banjo bolt clean with brake cleaner or similar. From the overboost protector you will find a tube that runs to the back of the intake manifold where it is connected with another banjo bolt. Repeat the removal and cleaning procedure as before. You may also want to blow the cleaner through the overboost protector, although I have no idea if this affects the reliability of the unit. Replace banjo bolts and lines.

There is no guarantee of power increase, however, for these 617 engines fitted with the EGR, soot often chokes off this VITAL passage and decreases the power. These lines are meant to transmit the increase in manifold pressure created by the turbo to the IP via the ALDA. So when the lines get choked off, turbo boost is not recognized by the IP and fuel flow does not increase with the air intake pressure boost provided by the turbo. The increase in power that some of us realize is because the tubes and/or the banjo bolts and/or the overboost protector were clogged. We clean them and all of a sudden we go from a 300D to a 300DT.