For Corolla 1.8L 4" Muffler Tip Catback+Manifold Header Exhaust System - 7th Gen E100 AE101 4A-FE Made of High Quality Stainless Steel Material TIG Welded CNC Machine Flange Increase High Flow Air and Maximize Performance; Instant Gain 10 to 15 Hp. / Tq.; Aggressive Deep Sound while Ensures Smooth Exhaust Gas Flow Catback - 4"(OD) Muffler Exhaust Tip with Removable Silencer; Inlet: 2.5"; Main Piping Diameter: 2.5"; O2 Sensor Bung Insertion Included Header - Metal gasket included / Inlet: 1.5" / Outlet: 2"