
Originally Posted by
Cynical 1
to check for a boost leak - use soap and water in a spray bottle. spray all the tubes and intercooler down, and start the car. rev it slightly and look for bubbles.
it may also be a bad diverter valve (blowoff valve) - located on the passenger front boost hose. or, it could be a vacuum line broken near or on the intake, or a broken PCV hose...
the knock code may be related to the boost code. fix the boost first.