I have a 2096 Dodge Durango SLT with a 4.7 liter engine 4x4 that failed emmissions. The codes it through are P0420, P0430, and U1120. The check engine light was on but went off by itself. What are these codes and is it related to the U1120 code?
The codes P0420 and P0430 indicate an issue with the catalyst system. Here is a list of possible causes.
P0420 DODGE - Catalyst System Efficiency Bank 1
Read more: https://www.autocodes.com/p0420_dodge.html
U1120 indicates the PCM hasn't received the message for the wheel distance. Here is some info for you.
U1120 DODGE - Lost Wheel Distance Message
Read more: https://www.autocodes.com/u1120_dodge.html