MILLTEK SSXFD236 Cast Downpipe with Race Cat FORD Fiesta Mk8 1.0T EcoBoost ST-Line 3&5 DoorDescription MILLTEK SSXFD236 Cast Downpipe with Race Cat FORD Fiesta Mk8 1. 0T EcoBoost ST Line 3&5 Door The range of cast downpipes is designed to enhance gas flow and heat management, increasing efficiency and performance. The standard OEM catalyst typically uses 500 600 cells, while the race catalyst reduces this to 200 cells. This results in a freer flowing catalyst, improving gas flow and performance. Cast downpipes designed for improved gas flow