the recent tire pressure thread prompted a search for add-on TPMS kits...has anyone used something like this?

https://www.schradertpms.com/en/our-...-retrofit-kits

 

I haven't, but I have looked into using something like this
https://www.minderresearch.com/tireminder/

You just screw on the valve caps for some of them to monitor pressures. I think the pass through versions have a bit better reviews and function better.

I would like a set up that I can easily change/remove sensors if needed. I have had internal TPMS sensors go bad and to replace them you need to dismount the tire. I ended up removing the TPMS from my 2011 Superduty after having a bad sensor, taking it to three different shops and each of them telling me the sensors test good, yet I still had the light on the dash. Also had a couple false triggers, once in the mountains well off the beaten path bouncing around on some old mining and logging roads. Another time was on the interstate when towing a small trailer with motorcycle on it. The light also went on during the winter when the temp dropped below freezing and would come on when I lowered the pressures when I wasn't towing. Filling tires with nitrogen helps a lot with the false trigger in winter but I don't have anyone in town that can do that. The factory sensors are set to go off below 80 PSI at least in the back, I think they're set for 65 PSI up front, and I don't like running my pressures that high unless I am towing something that requires that kind of pressure. With that in mind, whatever system you choose to go with, I would recommend you get a system that you can easily adjust what pressure triggers the alarm/indicator because you will need to if you live in an area with 4 seasons.