I have a 99 Suburban that is giving me problems, along with a Toyota (pre-drive-by-wire) in the fuel/ignition systems. The Toyota is quiet now, but looking toward the future and to diagnose the GMC right now I would like to get a code reader that will store the last x seconds/minutes of data and download to a computer to diagnose the actual problem(s). It is NOT giving any codes for the stuttering at speed or the hesitation. The last code it gave after months of major problems and backfiring was a MAF sensor, which I replaced with a used unit. This greatly improved the situation, but did not fix it. I changed out the MAP sensor with a new one and it is considerably better, but not right. Without the engine under load the problem does not seem to appear, only under load. I would like to be able to hook it up as I drive and after an episode hold the data in one of these units. Does anybody have any recommendations for a code reader that t will do this?
Mike D.