The CPA tool is a specialized tool that is capable of detecting cylinder performance concerns during hot idle, cold idle, and a road test. The tool is also capable of detecting performance concerns under any running conditions. The CPA tool helps troubleshoot cylinder performance concerns, including intermittent issues. System Requirements for PC: Windows 7 (32 bit or 64 bit). Used with 12-999-05 or 12-999-05M. ***Please note- refer to iKNow Article IK2700062 for further instructions on the CPA software needed to use this tool.