Fix both the burning oil smell and blue exhaust smoke problems associated with your 2015+ WRX turboback exhaust or Stage 2 and higher WRX by installing the PERRIN Turbo Sump Restrictor. The PERRIN Turbo Sump Restrictor makes the turbo sump more effective at sucking oil out of the turbo sump. This in turn creates a slight vacuum on the turbo sump creating a proper balance of exhaust pressure and vacuum on the turbo seals, significantly reducing the amount of leaking around the turbo seals. This does not change the oil flow to the turbo in any way. *Will NOT fix issues relating to blue smoke due to blown engines.