My nice Volvo's rear muffler has gone bad. I upgraded to the IPD sport system, which is 2.25 inches dia and all the pipes are fine, only the rear muffler needs replacement. I'm not overly concerned about loudness, lower tones would be preferred- but am looking for Highway Fuel Economy and power. The muffler guys I trust quoted me around $90 installed for what would similar to what I had with IPD system. What would be better performance and the Sporty Sound I like. Maybe specialist help here in Portland, OR area. THANK YOU! Sorry, I know everyone has probably asked these questions:}