If it's running 15PSI then it must be chipped. As to config of chip unless you have a reliable receipt to look at only other way is to open ECU as said and have a look at chip, normally it's printed on top at to what it's written for I.E Stage 1. Unless someone has put a 205 in a 4x4 car which wouldent make sense and wouldent last long with 4x4 it will be 200 block as standard.

High idle can be adjusted by means of a adjustment screw underneath throttle body must be done with car upto running temp, simply screw anti clockwise with a screwdriver until a idle speed of 850 RPM is achieved.

Knocking is proably top end related and is nothing to worry about (Hydralic Lifters), is the oil clean and has the car been standing a while?

From the sounds of it you may have a boost leak as I think your car would be at stage 3 + by looking at the spec of the engine and should make more than 15PSI.

Martin