Description
Scan tools that display live data are not necessarily expensive, and live data is a critical tool for the diagnosis of many engine trouble codes. Many people will knee jerk a generic mass airflow sensor replacement when faced with lean codes, without taking the minute or two to verify the diagnosis. That can be a double mistake because generic mass air flow sensors are not necessarily matched to the coding of the OEM computer.
Don’t forget to use your throttle to put the system under load while displaying live data, since the response will often point directly to the cause.