Replace the factory restrictive exhaust downpipe on your 6.4 Powerstroke with this 4" downpipe from Diamond Eye. The Diamond Eye 4" Aluminized Downpipe is of a two piece design that allows installation without cab removal and features the stock style ball/socket design and will directly replace the factory downpipe and bolt up to the existing exhaust post-downpipe. This kit is only available WITHOUT pre-installed bungs for the factory sensors, so you will have to provide provisions for that.