What is a common diagnostic tool used to troubleshoot engine issues?

An OBD-II scanner is a widely utilized diagnostic tool for troubleshooting engine issues because it interfaces with a vehicle's onboard diagnostic system. This system monitors the performance of the engine and other critical components. When a fault occurs, the OBD-II system generates trouble codes that can be retrieved by the scanner, allowing technicians to diagnose specific problems efficiently.

The scanner not only provides the trouble codes but also presents live data regarding engine parameters, such as temperature, speed, or fuel trim, which can lead to a more refined understanding of the problem. This makes it an invaluable resource for both professional mechanics and DIY enthusiasts when diagnosing engine performance issues, emissions problems, or other related concerns.

On the other hand, while tools like a torque wrench, endoscope, and pressure gauge have their use cases in mechanical work or inspections, they do not directly provide the comprehensive diagnostic capability offered by an OBD-II scanner. The torque wrench is primarily used for tightening fasteners to specific torque specifications, the endoscope helps in visual inspections of hard-to-reach areas, and the pressure gauge measures pressure levels, none of which can read trouble codes or real-time data from the engine management system as effectively as the OBD-II scanner can.