I just wonder if there is any way to monitor the dosing of DEF using the Scangauge
I haven't found any Xgauge codes for it. Its not in the list of standard parameters.
I just did a couple of hours of reading on DEF and learned some new things. Apparently contaminated DEF can cause damage to the copper substrate in the Catalytic Converter over time. DEF is 32.5% pure urea and 67.5% dionized water. Any contamination causes the water to ionize which cause salt chrystals to form and attack pumps, injectors, sensors and the copper substrate in the Cat.
The precise 32.5% blend also causes a 93% NOx reduction and losing that precise blend will drastically lower the NOx conversion rate. I think this is how the system knows that the DEF is not 32.5%. Water evaporation can cause the Urea concentration to change although I'm not sure how evaporation occurs in our Jeeps.
Precise control of dosing is critical also. I poorly controlled system may cause fouling of the Catalytic Converter as well. I suspect the latest TSB may be adjusting the control algorithm.
Knowing this...I wonder if bad DEF or improper dosing (poor control algorithm) isn't the big problem we are all seeing? The damage seems to occur over time.