jaymdee
it sounds like everything on your car is working fine, there are no hard and fast rules when it comes to the boost you will get when fitting de-cats and exhausts, everyone assumes that you will automatically get 1.2 bar, with full a de-cat and super dragger mine makes just under 1.1 when its hot and just over 1.1 in the winter, if you want more than the 1 bar you have you could try removing the restrictor ring and see what it boosts to, dont worry if it hits 1.4 bar it wont do it any harm just the once, you could then file a bit of the ring out and keep trying it till you are happy but remember without having a "smart" boost controller (as opposed to a bleeder valve) you will allways be prone to fluctuating boost levels with the seasons, can you trust the gauges you have tried, when i bought a second hand hks gauge i calibrated it at work as we have the gear and it was 0.8 bar out, lastly it may sound simple but have you checked all your intercooler pipework, hope my ramble helps