Piston - OBD2 Car Scanner
July 30, 2025
More About Piston - OBD2 Car Scanner
You will need an ELM 327 based adapter, either Bluetooth or WiFi, which you connect to the OBD2 socket in your vehicle. Piston will guide you through the connection process. You can access the instructions from the Home page after the first installation or from the Settings at any time.
With Piston you can:
• Read and clear Diagnostic Trouble Codes (DTCs) defined by the OBD2 standard
• Look into Freeze Frame data (a snapshot of the data from sensors at the time the ECU detected a malfunction)
• Access data from sensors in real-time
• Check status of Readiness Monitors (monitor emission control devices)
• Store the DTCs you read in a local history
• Login and keep the DTCs you read in the cloud
• Access the charts of the sensors readouts
• Export real-time data from sensors to a file
• Check the VIN number of your car
• Examine the ECUs details, like the OBD protocol or PIDs number
Some of the above are Premium Features and require a single in-app purchase that will unlock all of them. No subscriptions!
This application, in order to become a car scanner, requires a separate ELM327 based device, either Bluetooth or WiFi. Piston is compatible with OBD-II (known also as OBDII or OBD2) and EOBD standards.
All the vehicles sold in the USA from 1996 are required to support the OBD2 standard.
In the European Union, the EOBD was mandatory for petrol engined vehicles starting from 2001 and for diesel vehicles from 2004. For Australia and New Zealand OBD2 is required for all petrol cars made from 2006 and diesel cars made from 2007.
Important: This application can only access the data your vehicle supports and provides via the OBD2 standard.
If you have any questions or suggestions you can contact us at support@piston.app.
Latest Version
3.9.0
July 30, 2025
Stinez Pty Ltd
Internet
Android
1,294,352
Free
com.clockworkbits.piston
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User Reviews
Florin Ionescu (Einstein65)
2 years ago
Even there are 3 permanent errors on dashboard, your app doesn't read them. Not worthy.
A Google user
5 years ago
Small, simple, elegant app with almost everything you could want in an obd reader and nothing you don't
bruce carter
2 years ago
piston car scanner is great i love it, until i upgrade and now it will not connect i have tried several times with no successes i am disappointed,please could you help?
Cole Gerdemann
1 year ago
Great! Very simple and clear UI. Only OBDII reader app that works well and doesn't look like it is 6+ years old!
Marox
2 years ago
Exceptionally good! This is one of the best obd II apps. Simple yet very straight forward and efficient! I still have to test the new update but it looks already very good!
A Google user
5 years ago
One of the few working with all BT dongles and without tons of useless options and ads. Good job.
J M
4 years ago
Most often tasks are connect Bluetooth, load faults, clear faults. Would it be possible to make these steps a widget, only requiring one click to do all three?
Tim O' Callaghan
4 years ago
Very nice and clear UI, I just wish I could log the real time data being displayed too. If that is or was possible, it would be the complete package.
Christian Step
2 years ago
Excellent so far for FREE! Found this ap when the "torque ap" I used with my veepeak Bluetooth scanner stopped being free. Piston is actually SO good with its data charts I think it's WORTH buying!
A Google user
6 years ago
Good app for quick info from a Bluetooth ODB2 reader. Interface is a little clunky at times and doesn't display all the info that other apps might. Overall, I'm happy with it.
Cevin Cochran
1 year ago
Worked great for saving me a trip to the repair shop! I thought it was faulty O2 sensors, all reading good, turns out it was a dead EGR valve, no voltage. 2007 Ford F150 6cyl manual trans, still going strong.
Lawrence Bartling
2 years ago
Update ruined it. with wifi dongle it shows it being connected, but it just keeps telling me to connect scanner. Worked perfectly before the update. **update** lights all doing what they're supposed to. have since deleted this app, other well reviewed apps still function flawlessly with ELM327 wifi.
Rick Boiter
1 year ago
Great app, liked the cleaner interface before the 2023 update but it still works well. I'd give five stars if it displayed on Android Auto so I didn't have to grab my phone to see real-time data while driving.
Eric Laney
5 years ago
Just started using, having trouble figuring it out. Instructions would be nice. I have no check engine light lit up or code at the moment on my truck, maybe that's the problem. Scanned for faults and it just sits there. Seems like is should say no codes found. The function buttons at top of screen are not labled.
Bartłomiej Piguła
2 years ago
This app has served me well for so long... and continues to do so. I bought premium, as the price is great for value, and functionality (especially logging) is superb. Interface is clean, and easy to navigate. Best OBD reading app for me.
Brian Timms
2 years ago
This App was great until the recent update, now it's a big effort to get the app to connect to EM327 dongle, and what was once a simple to navigate and understand interface now requires a lot more concentration that it should. No longer as user friendly and simple to use, so harder to recommend to non-tech friends.
LAURA-ANN CHARLOT
3 years ago
App has a simple interface, and is ad-free which is nice, but it's extremely limited in the number of PID's that it can read. All of the supported PID's are related to the ICE. There is no support that I could find for Hybrid system functions like traction battery state of charge, battery/inverter temperature, or power flow. This app is of little use to owners of hybrid vehicles, unfortunately. It's not a bad app, just too limited for what I need for a Prius PHEV.
A Google user
2 years ago
After having tried many of the popular OBDII apps, this is the one I stuck with. Clean interface, the UI is simple to navigate, and no irritating ads. Connected quickly to my BAFX Bluetooth scanner and easily cleared and found issues. 4 stars given for inability to locate MAP sensor issue, but to be fair, similar apps did not find the issue either.
Sam Yahres
2 years ago
Connects but won't read any live data from my Elm327 Bluetooth dongle, which works fine with both Car Scanner and Torque Lite. Car is a 2013 Honda CR-V. Very disappointed. ** UPDATE ** My bad. I didn't notice the "Play/Pause" icon on the live data screen. Pressing "Play" resulted in the display of the data. My apologies to the developer. Changed rating to 4 stars for now. Will update after further testing.
Cora Taylor
1 year ago
Of all OBD2 apps available on the play store, this is the one I've settled on. Take that for whatever it's worth, extra star for including a 7$ One-Time purchase for features that other apps would require a subscription for. Isn't the most feature-filled, but what's here is sold and it's a cleaner UX than most apps I've tried, which feel.. rushed.
