4-2-1 Exhaust Header for Honda Accord 2.4L

The DC Sports HHS5022 is a performance header engineered for the 2003-2007 Honda Accord 2.4L models, specifically those with the K24A4 engine. Its equal-length, 4-2-1 design is optimized to enhance midrange power delivery. Constructed from durable T-304 stainless steel, the header features precisely mandrel-bent runners with a 1.8" primary tube inner diameter and a 1.9" collector inner diameter. All joints are hand TIG welded both internally and externally for superior strength and smooth airflow, while CNC machined flanges ensure a flat, leak-free seal against the cylinder head. This header boasts 50-state legality, carrying CARB Executive Order #D-370-14, which means it meets strict emissions standards and is street legal in all states, including California. Buyers have the choice between a polished stainless steel finish or a ceramic coated finish, which helps to reduce underhood temperatures. During installation, it is crucial to replace the exhaust manifold gasket and consider new manifold studs or bolts if the originals are worn. The header bolts should be torqued evenly in a crisscross pattern to factory specifications to prevent flange warping. It is also recommended to recheck and retorque the bolts after the first few heat cycles, as headers can settle. Ensuring a proper seal at the connection to the factory catalytic converter is vital to prevent exhaust leaks and potential check engine light (CEL) codes that can arise from O2 sensors detecting unmetered air.