Fix both the burning oil smell and blue exhaust smoke problems associated with your WRX turboback exhaust or Stage 2 and higher WRX by installing the PERRIN Turbo Sump Restrictor. Many customers experience a burning oil problem or blue smoke coming from their exhaust after installing aftermarket J-Pipes or turboback exhaust systems. Installing these parts on 2015+ WRXs (FA DIT engine) causes a change in exhaust pressure, allowing engine oil to escape out the turbo seals. This leaks into the exhaust creating the burning oil smell and blue smoke that many people see. Cars with catless J-Pipe setups experience this issue much more than cars with high-flow cats. Sometimes after installing aftermarket exhaust components such as a j-pipe, or a complete turbo back will change the exhaust pressure which will allow the engine oil to escape out to the turbo seals. The oil will be pushed to the exhaust which will create the burning oil smell, as well as the blue smoke that people will see.