Postby smj999smj » Tue Apr 11, 2017 12:53 pm
I eliminated my post cats with Doug Thorley mid-pipes and replaced the stock muffler with a Magnaflow #12580. I also installed Doug Thorley shorty headers. Honestly, I did really notice that much improvement in performance and nothing in gas mileage. What I did notice is that it is a lot louder than stock and there is that familiar "drone" noise common with performance mufflers, especially after 1000 miles. If this is the only mod you are doing to your Pathy, you would be better off spending your money on a tuner like Bully Dog or Superchips (which is what I went...but I also installed an XRP plenum spacer and an aFe Momentum CAI system).