iPhone Screenshots


FourStroke is a powerful tool that analyzes and displays real-time vehicle sensors and data through your vehicle's OBD-II port, a port standard on most vehicles across the world. Use of this app requires a compatible OBD-II Wifi Adapter. Our app is FREE to pull and clear engine codes along with most other functionality! FourStroke will work with any non-proprietary OBD Wireless adapter.

FourStroke can convert your iPhone into a heads-up display of just about every sensor your car supports, without needing expensive gauges. Sensors include RPM, coolant temperature, vehicle speed, air flow, O2 sensor data, and more (sensor support varies based on vehicle).

Quickly diagnose a check engine light (CEL) by pulling up exactly what error codes are present. FourStroke automatically turns the code into a readable description. Your vehicle also may store 'Freeze Frames' that detail what sensor data was present when the CEL first occurred; FourStroke can display this information for you.

In app purchases are availble for reading more advanced sensors as well as a performance unlock for a dynanometer (horsepower & torque reader) and a 1/4 mile analyzer (which is only partially limited for free users).

DISCLAIMER: This app requires a third party OBD2 adapter. Please visit our website for details. Like most others this app does NOT support ABS codes. Bluetooth adapters are not supported.

What's New

Version 3.1.0

=== Version 3.1.0 ===

Minor Enhancements
-Added new sensor 'Intake Manifold Boost Pressure'
-Added clarification on App's abilities for code clearing
-Simulated ECU now shown as different icon on home screen
-Added additional gauge screens

Bug Fixes
-Iphone X home bar no longer covers dyno results
-Table headers no longer become hard to read after scrolling

=== Version 3.0.1 ===

Major Enhancements

Performance section added
-1/4 Mile Run

iPhone X Compatibility

Minor Enhancements

Added option to allow forcing English language
Error code detail screen links to third party website for further details
Added code lookup feature
Gauge value overrides now allow negative numbers

Ratings and Reviews

4.4 out of 5

105 Ratings

105 Ratings

Must recommend


Detailed information and able to clear codes just download.
Purchased premium to access other features
Thank you creator for this awesome app

Great App!


Unlike the others that make you pay for any of the useful info, this one gives you some great basics and can pay for deeper details if you need it.

Best ECU checker for iOS


With the proper hardware this is by far one of the best engine metrics tools out there.
Simple to use and great info if the ECU provides the data.
A most for track days and autoX days!


Mike Morawski
39.1 MB
Requires iOS 10.0 or later. Compatible with iPhone, iPad, and iPod touch.
English, Russian
Age Rating
Rated 4+
© 2017 Mike Morawski
In-App Purchases
  1. Sensor Upgrade Package $3.99
  2. Performance Upgrade $2.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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