My car's performance has slowly been declining. It will run fine sometimes. I am only putting out 10 pounds roughly but it seems like it should be performing better than it is. I dont know how often they should be tuned for a turbo motor but I would say it's been around 15-20,000 miles ago. I know I should probably get an adjustable fuel pressure regulator because the car runs a little lean according to the gauge and I have an open K&N so that probably adds more air to the mixture. Any help would be appreciative.