A check-engine light is a symptom, not a diagnosis. The code a parts store reads off your car names a circuit, not a failed part — and replacing the part the code mentions is how people spend four hundred dollars and still have the light on. A misfire code can be a coil, a plug, an injector, or a vacuum leak feeding one cylinder.
Diagnosis here means pulling the codes, then testing the actual system: live data, fuel trims, and where the readings drift from what the engine should be doing. You get told what failed, what it costs to fix, and what happens if you leave it — before anyone touches a wrench.
Describe what the car is doing — the noise, when it happens, what changed. Half the diagnosis is in the description.
What actually failed, what it costs to fix, and what happens if you wait — before any work starts, not after.
The repair gets done and you get told why it failed, so you know whether to expect it again on this car.
★★★★★“I've been going here for a couple of years now for various repairs (new brakes, shocks, lower control arms, etc.) and I'm always impressed not only with how fast they diagnosis and the quality of their work, but also the price.”