Guys, It seems that the reason for the sluggish performance was my petrol filter. Since my old man drives the car and barely goes over 1.5K revs cruising the suburbs he really didn't feel the difference, after changing it. I drove the car on the weekend and it feels like a different car...its no slug any more... I have previously changed the petrol filter once before, but for some reason this time it made a big difference. Now I'm thinking this might be the reason my car has pinged once or twice... Out of curiosity would a clogged filter lead to a lean condition, and trigger off the knock sensors, hence retarding the timing, and causing the car to drop power? As the car feels much stronger now off boost, and on boost, even though its still making the same PSI as it was pre filter change.