Which item is typically not required information before performing an I/M test?

When preparing to perform an Inspection and Maintenance (I/M) test, certain pieces of information are typically essential to ensure the vehicle meets the required emissions standards. In this context, the Gross Combined Weight Rating (GCWR) is not commonly required information.

The GCWR is primarily used for assessing the towing capacity of a vehicle rather than for emissions testing. It indicates the maximum weight a vehicle is rated to safely tow, which is not relevant to emissions performance. In contrast, emissions equipment, the Vehicle Identification Number (VIN), and engine size are all critical factors that help determine the emissions levels and compliance with environmental regulations.

Emissions equipment is necessary to verify the presence and functionality of components designed to control emissions. The VIN is crucial for identifying the specific vehicle and its corresponding emissions standards, while the engine size can influence the emissions output due to differences in engine design and performance characteristics. Each of these items directly relates to ensuring the vehicle is in compliance with emissions regulations.