I was told the same thing about the engines over there having to be replaced every 40-50k miles because of emissions when I bought a jdm engine for my wifes old crx. I'm not sure if it's true or not but it would suck to have to replace your engine that often. It kind of makes sense though. Everyone says that the jdm engines are pretty beaten up when they get them. Well if you are only going to have it for 50k why not run the piss out of it. Also explains why there are so many jdm engines available for import and they're cheap.