I have the '98 ecm and all I personally know that is wrong with it is that some of the programming software out there(Predator) isn't compatible. Which in my opinion is enough to upgrade to a later model. My local shop can't dynotune it bacause they have the predator software, so I either have to drive hundreds of miles for a dynotune or get a mail order tune which I've already had done and my A/F ratio is way lean.