Error code 15733 - NOx catalyst Bank 1 (Solution)

Error Code
[quote]15733 - NOx catalyst Bank 1
P20EE 00 [101] - Efficiency too low[/quote]
This can occur in various TDI engines when the engine control unit (ECU) believes the efficiency of the SCR system is too low.

It is recommended to follow the following procedure:
- Ensure that the AdBlue tank is filled with the correct solution.
- Check if there is a software update available for the ECU. See:
<a href="/viewtopic.php?t=28184" target="_blank">Check the software version</a> - Check the NOx sensor and its wiring.
- The <a href="/viewtopic.php?t=3095" target="_blank">AGR System</a>
- Before replacing the NOx sensor (sensor is expensive), you can try cleaning it.

After replacing or cleaning the NOx sensor and deleting the error in the engine control unit, the warning light on the dashboard remains lit. Either drive for a few kilometers and hope that everything now works, or:

- Delete the error in the engine control unit.
- Use VCDS under 01 - Engine Electronics (MSG).
- Select the basic settings.
- Select "SCR Efficiency Check" from the drop-down menu.
- Click "Start".
- Press the brake and accelerator (the display will prompt you to do this, the engine speed will rise to around 2000 rpm and the glow plug indicator will light up in the dashboard).
- Remain in this state for about 5 minutes.
- The process is complete when the engine speed drops. At the same time, a message will appear in VCDS.
- Check if the message on the dashboard has disappeared.

See also:
/viewtopic.php?t=30407