I don't know if this will help you, but if you go to
www.mass-floefi.com they have a EFI setup that uses an OEM mass air sensor. I haven't heard anything bad about this setup, but by no means should you consider me an expert! This is the system I'm planning on putting on my car when it gets back from the shop. One of the things that I like about this system is that I don't need to carry a laptop around with me if I encounter big elevation changes on long road trips.