The air intake boot that is between the CCV adapter and turbocharger. The stock boot reduces the 4" intake port down to the 3" stock TP-38 and GTP-38 on the 1999.5 - 2002 Powerstroke 7.3L Diesel.The Early 99 requires a different intake boot.
NOTE:On the 1994-1997 PowerStrokes, this will not replace the original orange intake boot. The intake boot upgrade kit, part # 9-032 includes this boot. You can replace the intake boot with our aftermarket boot, part # 9-039, a direct replacement boot.