02-06 Nissan Sentra SER Spec-V 2.5L Stainless Steel Exhaust Header 03 04 05 4-1; 1 piece (Gasket is included) Gain More performance Due to More Air Flow Increase Horsepower and Torque Mandrel bent tubing, CAD-rendered, CNC Machined Flanges. Utilizes factory 02 sensor position