In some cases, sensor connectors in your 6.6L Duramax can become loose or break causing a poor connection between the connector and the sensor. This can lead to intermittent issues or a complete failure of the sensor all together. The Fleece Performance Crankshaft Position Sensor Pigtail will allow you to repair the connector and ensure a proper connection between the connector and sensor. This kit includes heat sealable butt-style connectors.