I've got a dump valve so I could try that do you think ? As it ran fine on that agers ago but after joining here I noticed people saying to remove them, it's plunmed into the fbr aswell mate with all new proper vacuum pipe too the rocker pipe the 90 degree pipe you was onabout I've just replaced with a new genuine pipe, i had a idea earlier the noise in getting could that be the waste gate opening? When it shouldn't be, it's strange to be honest I had a new down pipe fitted 2.5 inch same as the old one but a day after that I had boost issues I've looked at the down pipe it looks ok there's nothing I can see around it the exhaust place could have caught