The next article on wideband O2 sensors and high overlap cams was very interesting. I had heard about how self-learning ECUs could think idle was lean due to lots of unburnt oxygen and add fuel when the extra oxygen actually was coming from the overlap. And in another article, they showed what the computer would due if you had a bad spark plug wire (it added fuel). EFI is neat but you have to understand what the sensors are telling you and how the system is reacting!!