OBD JScan

It not only reads the code, like P0171, but gives you a plain-English explanation and lists common causes, such as a vacuum leak or faulty sensor. You can also view live data, like fuel trim numbers, to help confirm the issue yourself.

Yes, you can build custom dashboards to track parameters like transmission temperature, but finding that feature takes some digging. The interface is a bit dated and lacks tooltips, so you may need to explore the menus to set it up.

This is a common issue on iPhones where the app disconnects if your screen locks. To fix it, you can adjust your phone's display sleep settings to stay on longer while using the app, or try a different Bluetooth adapter for a more stable connection.

First, make sure your phone's Bluetooth is on and the adapter is in pairing mode. Then open the app and follow its connection steps—sometimes you need to manually select the adapter from a list. It can feel clunky, but once paired, it usually stays connected.

While it can't replace a mechanic for complex repairs, it gives you the same core info—like trouble codes and live data—that a shop would use, saving you a $100+ diagnostic fee. The trade-off is that the app's interface is less polished and takes some learning, whereas a pro's tool is more straightforward.