Why Nick and Stefan Motor Works Finds Faults Other Garages Miss

15 February 2026 · 5 min read

The difference between reading codes and finding faults

A fault code tells you what system or circuit the engine management has detected a problem in. It does not tell you which component has failed, or why. A P0300 random misfire code could be caused by a spark plug, a coil pack, a fuel injector, a compression leak, a vacuum leak, or a crank sensor — all giving the same code.

Clearing a code and telling the customer to come back if the light returns is not diagnosis. It is delay. A good diagnostic session starts with the fault code, then uses live data from multiple sensors, component activation tests, and physical inspection to narrow down the actual cause. This takes more time and requires more knowledge — but it results in a correct repair first time.

What live data actually shows us

Live data allows us to watch every sensor in real time while the engine is running — fuel trims, injector pulse width, oxygen sensor output, throttle position, EGR valve position, boost pressure, temperature readings, and much more. Comparing these values against expected ranges tells us whether a component is performing as designed or not.

Intermittent faults — those that come and go without a stored code — are particularly well suited to live data analysis. We can set up the data stream to capture the moment a fault occurs, giving us direct evidence of what changed and when. Customers who have had an intermittent fault dismissed elsewhere often find that live data recording reveals exactly what is happening.

When we cannot find a fault the same day

Some intermittent faults do not present during a normal diagnostic session. We tell customers this honestly rather than guessing. In some cases we can send the car home with a data logger and ask the customer to return when the fault has occurred so we can analyse what was captured.

We do not charge for a diagnostic and then shrug. If we have carried out a thorough session and not found a clear answer, we discuss options with the customer and agree the next step. That honesty is part of what brings customers back — and part of what brings customers from other garages after they have had a different experience elsewhere.

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Talk to the team at Nick and Stefan Motor Works in Brierley Hill — honest advice and a straightforward booking.

Call 07494 990846