H&S XRT Pro Installation & Operation Manual page 39

Urea / scr system
On the 2011 - 2013 6.6L LML Duramax, there is a UREA system that needs to be unplugged
when running High Sulfur tuning. The UREA system must at least be unplugged but can
be completely removed from the vehicle if desired. Failure to unplug the UREA system may
result in a check engine light and/or dash messages, erratic engine operation, and loss of
power. Follow these instructions to unplug the UREA system:
1. The urea injector is located between the CAT and DPF above the torsion bar cross member.
Unplug the electrical connection and the urea line.
2. The main urea harness is the large black harness located near the urea injector above the
urea tank. Flip the large gray locking tab to disconnect the harness.
egr emissions equipment
If you are installing H&S High Sulfur tuning, you must unplug the EGR system on your 6.6L
LML Duramax if not installing a complete EGR delete. Failing to do so may result in erratic
engine operation and loss of power. Please follow these instructions carefully to unplug and
disable the EGR system:
For complete UREA System Removal instructions, visit
www.hsperformance.com/tech
1-888-628-1730 • XRT Pro Installation Manual 39