KlaroWhat it is good for, day to day
An OBD2 adapter is not a one-off purchase for the day the light comes on. Here are the eight situations where it genuinely changes something — and one where you should leave it alone.
The check engine light just came on
The obvious use, and the most useful. Within two minutes you know whether the fault is a tired sensor or a misfire destroying your catalytic converter. You call the garage knowing what you are talking about, and you will know whether the quote matches the problem.
A fault is brewing, with no light
The control unit records “pending” codes before it lights anything up: a fault seen once, not yet confirmed. Klaro reads them alongside the rest. It is the only way to see a breakdown coming, and nobody thinks to look.
You are buying a used car
Plug in before you sign. You read the VIN, the stored codes and the pending ones. A seller can clear codes that morning — but a real fault returns quickly, and pending codes often reappear within the first few miles of a test drive.
After a repair
The real test is not that the light is off, it is that the code does not come back. Drive for a few days, read again: if the code has returned, the fault was not the one you were billed for.
You do your own repairs
You have replaced the sensor, the EGR valve or the battery: the light stays on until someone clears the code. Until now that meant a trip to the garage for a thirty-second job, often billed. Klaro clears it from your phone, ignition on, no appointment. That is the feature reserved for the Pro version.
Your battery worries you
Voltage reads live. Engine off, a healthy battery stays above 12.4 V; running, the alternator should bring it to between 13.8 and 14.4 V. Two numbers that tell a tired battery from a failing alternator.
You drive a diesel
The DPF & EGR screen follows the particulate filter's differential pressure and exhaust temperatures. A climb past 500 °C means a regeneration is under way: not the moment to switch the engine off, and recognising it keeps the filter from clogging.
You want to understand your engine
Over a hundred readings come live: revs, load, ignition timing, intake and coolant temperatures, air flow, oxygen sensors. The dashboard is yours to compose, tile by tile.
When to leave it alone
Do not clear codes right before a roadworthiness test. Clearing also resets the control unit's emission monitors, and a vehicle whose monitors are not ready is failed. Expect several dozen miles of varied driving before they revalidate. And remember that clearing a code switches the light off without repairing anything.
What you need
An OBD2 adapter plugged in under the dashboard, and the app. Nothing else, not even an internet connection.
