The air intake heater (AIH) is designed to help heat the intake air charge, making cold starts easier and less smoky. However, many remove it for increased airflow and/or because they're tired of fixing the system (the relay that controls it is a common fail item). Unless you live in a very cold climate, removing the AIH comes with no negative side effects. When the AIH is removed, the hole it previously occupied in the intake needs to be plugged, or else a massive boost leak will exist. That's where the Riffraff Diesel AIH Delete Plug comes into play. The Riffraff AIH Delete Plug is a 100% USA-made billet aluminum piece designed to plug the intake for those who have removed their AIH. It threads right in with no other modifications needed. It also comes with a 1/8-inch NPT plug that, when removed, is the perfect place to grab a boost reference for boost gauges, and for those pushing their 7.3's harder than most of us, it's a perfect spot to plumb in nitrous systems. The Riffraff AIH Delete Plug comes in three different anodized finishes and utilizes a Viton O-ring for perfect sealing abilities.

Check It Out!: https://www.riffraffdiesel.com/aih-tapped-plug-99-5-03/

NOTE: For those looking to remove their AIH, this code eliminator is needed to prevent any diagnostic trouble codes the system produces when it's not seeing the voltage it expects to see when the AIH is working properly:  https://www.riffraffdiesel.com/air-intake-heater-plug-code-eliminator

Air Intake Heater Plug Code Eliminator for Ford 7.3L 99.5-03

Image courtesy of dieselworldmag.com (see the full article HERE)