[cewrx7r1]

I have done the Mazdatrix (RB) mild and PineApple medium ports to engines, and they idle smooth with no sign of loping.

If you turn off the normal idle control system and manually tune idle timing and fuel, you can not only achieve a smoother idle but also leaner. That will be in the range of about 12 degrees IGL idle timing instead of the patheic retarded values that Mazda uses for emmisions control.