Hope this will help you
Coolant leak from under the uppper intake manifold
these videos will also help you with replacing the gaskets
in the plenum and get to the EGR ports (171 and 174 Codes)
part 1
http://www.youtube.com/watch?v=AWomi-tfjoc
part 2
http://www.youtube.com/watch?v=46T9DTYeppM
Blend Door Actuator
http://www.youtube.com/watch?v=2tN2nZjjw_M