PA Emissions Inspector Certification Practice Exam

Which speeds are tested during the two-speed idle test?

1. 1500 and 2000 RPM

2. 2500 RPM and idle

3. 3000 and idle

4. 1000 and 2500 RPM

The correct answer is: 2500 RPM and idle

During the two-speed idle test, the speeds that are typically tested are at idle and at a higher RPM, specifically around 2500 RPM. This testing method evaluates the emissions produced by the vehicle under both low-load and higher-load conditions. At idle, the vehicle is in a low power state, which is critical for assessing emissions at a normal operational condition, while the 2500 RPM speed represents a higher throttle position that places greater demands on the engine, ensuring that exhaust emissions are evaluated under varying conditions commonly encountered during normal driving. This method provides a dual perspective on how well the vehicle's emissions control systems function across different engine speeds, which is crucial for determining compliance with emissions standards. Other speed combinations do not align with the standard protocols for such testing, as they either do not represent a realistic operational range for vehicles or exceed typical RPM parameters used in emissions testing practices.