Exhaust leaks seem to be an all-too-common issue with most modded Subaru’s. They tend to spring up out of nowhere and cause hours of troubleshooting headaches. One of the most common leaks that we hear about is from running an OEM downpipe with an aftermarket 3" catback without a proper adaptor. Use an adaptor that allows you to retain your stock donut gasket for the best solution to finally end that pesky leak. CNC machined from mild steel and zinc coated for durability and longevity, this thing will outlast your car. Don't waste your time trying to get your OEM downpipe to seal without a donut gasket. In a short amount of time, they rust and corrode and will prevent you from ever getting a good seal with a typical flat gasket. Re-use your stock donut gasket along with a GrimmSpeed 2x Thick 3" Gasket for a perfect seal on the first try!