Logging refers to recording data from the ECU. This data is then analyzed and used to make tuning related decisions. In order to tune your car you must be able to log data. In fact data acquisition and analyses tools may be considered the most important part of tuning your car. In order to effectively tune your car you will need a Logging Cable, logging software such as EvoScan or MitsuLogger and a Wide Band Air Fuel Meter. You will need the ability to analyze the data as well. EvoScan includes some data analysis tools such as graphing and map tracing. You may also want to use a tool called Data Log Lab. Excel can also be used to help analyze logging data.