Upon 12 years of old subaru, not one season survived OEM exhaust systems without needing something.
when an engine is mastered in clean burn to begin with, it could care less about exhaust. I started with a dymoax muffler and SAE 2 inch piping aluminized (cooler, and very cheap, expendible)
Humoring todays standards for a compltete system was difficult. I could have no catalyst honeycomb in the resonator, it made some type of bomb in my locale in the spring time. i found this to be a cure for the hot catalyst not far in front of this resonator. I needed one with no catalyst, just a staller/filler for catalyst to heat quick in cold and not backfire through muffler. so far it has worked.
it is remnants of a 24 inch glasspack, supposedly 12 guage in and out. So far it sounds good, and the exhaust smells clean. It ince again gets extremely hot, like oe resonator, except, there is no danger, it is just a kiln now. I gave the convertor the room it needed, and no snappy twack noises in the cold after letting off throttle.
heads up if you are leaning the old carb ecomodders...
