Hi I have a 2001 Etech 470, something strange happening with the boost pressure and power. I havent seen the boost gauge go over 150kpa for a few months truck felt a bit like it had lost some power but I thought must be my imagination then last week going uphill the truck made a completly different sound and took off up the hill like a rocket looked at the boost gauge it was reading 225kpa since then it has been up and down noticeable sound difference and gauge pressure when its going well. not showing any fault codes, the mechanic had a look changed 2 hoses on the intercooler and a sensor also sometimes the tacho will go up fast and sometimes slow on the same road in the same place sort of feels like driving into a headwind or soft ground if anyone has any ideas what could be happening that would be great thanks