LG John

After hours of cleaning the scooby I took her for a wee drive and opened her up a few times. I noticed after an 'incident' with a Jag XJS that the car seemed noticeably slower and I did a couple of 2nd and 3rd gear fully throttle runs and only got 1.0 bar (peak) of boost. When I got the car from autoscooby it was 1.1 bar and I haven't touched a thing? What could cause this, should I be worried?

The mats I inherited are a little on the large side so I'll check tomorrow and make sure they aren't fouling the accelerator