Freedom251 › Hardware Diagnostic Software
Piston
What Piston is
Piston turns an Android phone into a scanner for OBD2 vehicle diagnostics. It can read and clear diagnostic trouble codes, display Freeze Frame data, and show live sensor readings. A separate ELM327-based adapter is required; it connects to the phone by Bluetooth or WiFi. The app supports OBD-II and EOBD standards, but can access only information a vehicle makes available through OBD2. Its free plan costs nothing and includes the core code, Freeze Frame, and live sensor functions. A single in-app Premium purchase, handled through Google Play billing, adds sensor charts, live-data CSV export, Readiness Monitors, fault history, cloud sync, and VIN reading. Some older vehicles may not support VIN readout. Piston uses Firebase services for functions including crash reporting, analytics, authentication, and cloud storage. Its privacy policy says remote data is encrypted; Settings provides opt-outs for several data services. Users can delete their account in the app, permanently removing related data such as historical fault codes. Support is available by email.
Who it suits
Piston may suit Android users who want to read OBD2 diagnostics and sensor data, provided they have a compatible ELM327 adapter. Drivers should check whether their vehicle exposes the data they need.
What it does well
- Free plan reads and clears fault codes
- Shows Freeze Frame and live sensor data
- Premium adds CSV export and sensor charts
- Account deletion removes associated historical fault codes
What to know first
- Requires a separate ELM327 adapter
- Access depends on vehicle-supported OBD2 data
- Some older vehicles may not support VIN reading
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Free | Read and clear fault codes · Read Freeze Frame data · Real-time sensor data | Free |
| Premium | Pay once, use forever · Real-time sensor charts · CSV export · Readiness Monitors · Fault history and cloud sync · VIN reading | On request |
As piston.app lists them, read 4 Oct 2026. The maker's own page has the final word.
Verdict
Piston offers core code and sensor reading at no listed plan charge, with additional tools through a one-time Premium purchase. The adapter requirement and vehicle data support are important checks before relying on it.
Facts from Piston's own pages
- Adapter required
- The app requires a separate ELM327 based adapter that connects by Bluetooth or WiFi. · piston.app, 4 Oct 2026
- Data deletion
- Users can delete their account from the app, which permanently deletes associated data such as historical fault codes. · piston.app, 4 Oct 2026
- Diagnostics
- The app can read and clear OBD2 diagnostic trouble codes, view Freeze Frame data, and access live sensor data. · piston.app, 4 Oct 2026
- Headquarters
- Sutherland, New South Wales, Australia · piston.app, 28 Sept 2026
- Integrations
- The app uses Firebase services for crash reporting, performance monitoring, analytics, remote configuration, authentication, and cloud data storage. · piston.app, 4 Oct 2026
- Maker
- The Google Play listing identifies the developer as STINEZ PTY LTD and gives an address in Sutherland, NSW, Australia. · play.google.com, 4 Oct 2026
- Notable limitation
- Some older vehicles may not support VIN readout. · piston.app, 4 Oct 2026
- Payment
- Premium is a single in-app purchase with no subscription, and payment is handled through Google Play billing. · piston.app, 4 Oct 2026
- Premium features
- Premium adds sensor charts, live data export to CSV, Readiness Monitors, fault history, cloud sync, and VIN reading. · piston.app, 4 Oct 2026
- Privacy controls
- Users can opt out of crash reporting, performance data, remote configuration, and analytics in Settings. · piston.app, 4 Oct 2026
- Purpose
- Piston turns an Android mobile device into a car scanner for reading diagnostic trouble codes and Freeze Frame data. · piston.app, 4 Oct 2026
- Security
- The privacy policy says data sent to remote servers is encrypted and the app uses the Play Integrity API. · piston.app, 4 Oct 2026
- Support
- Support is available by email at [email protected]. · piston.app, 4 Oct 2026
- Vehicle standards
- Piston is compatible with OBD-II and EOBD standards and can access only data the vehicle supports through OBD2. · play.google.com, 4 Oct 2026
Where Piston stands on Freedom251
- Hardware Diagnostic Software#18 of 26