OBD II 5.9 swap evap. codes?

Don't know what year you're using, might be a problem working around the CCD bus signal. It's a digital signal transmitted by the PCM to a microprocessor where it's decoded for the gauges and such. I think it was Jeffthecomputerman that posted about a phone/tablet/laptop app that will decode for all of those functions. Less than $20. The post is in this section - Magnum swaps.
Hope this helps some.

BTW, you will probably throw so many codes that the light won't do any good! You could use it as a map light! LOL
I would suggest wiring in the Data Link Connector (DLC) to hook up a code scanner. Maybe they have a cheap app for that.