Automobile(s): 2006 STS V8 AWD, '95 Ford Ranger Join Date Jul 2004 Location Fairbanks, Ak Age 75 Posts 27,218 Re: Need help with Check Engine Light With a scan tool such as the Autoenginuity you can read out the MAF signals as well as throttle position and other data and compare it with expected outputs as outlined in the factory service manual.