I'm not a big fan of add on ECM stuff - VAFCs are ok but very limited - good for someone that doesn't want to mess with ECM programming. If you don't know what you're doing with it, you could hurt your engine. I'm sure the reason why there are so many of them on ebay is what I stated before. I'd rather use hondata or other chip editing software unless you need to do some trial and errror tuning, then I guess the VAFC is helpful.