If you're looking for a reliable back pressure tube for your 7.3 Powerstroke 1999.5-2003, look no further than the Alliant AP63404. This OEM direct fit replacement is built to last, and will keep your truck running like new. Over time, back pressure tubes can blow out and set a service light. With the Alliant AP63404, you can rest assured that your truck will be running smoothly for years to come.