The readiness monitors on Emission Tests say whether each self-test has run. This screen shows what each test measured: the last value and the lower and upper limits the manufacturer set (OBD service 06).
It helps to spot a component drifting towards failure before the check engine light comes on.
Connect with the car stopped
Connect the adapter, turn the ignition on or start the engine, and keep the car stopped. The reading is refused while the car is moving.
Tap Read
The app asks the car which monitors it has and reads each one. A sheet shows the progress, and you can cancel at any time. On the free plan the reading starts after a short ad.
Read the results
The tests are grouped by monitor: catalyst, oxygen sensors, EGR, evaporative system, misfire and others. Each line shows the value, the limits and a state. Turn on Show only tests out of limits to see only what needs attention.
Compare with earlier reads
The last 20 reads of each car are kept on the phone. Tap Previous reads to open an older one. Saved reads open without connecting and without an ad.
- Within limits
- The last result is inside the limits set by the manufacturer.
- Out of limits
- The last result is outside the limits. It often comes before a fault code for that monitor.
- Not tested
- The test has not completed since the codes were cleared or the battery was disconnected.
- No verdict
- The car sent limits that contradict each other, so the app does not judge the value.
- Show only tests out of limits
- Hides the tests that are within limits.
- Previous reads
- Opens one of the last 20 reads saved for this car.