so i did a search and i found a few things... most people like it, but some mentioned that the manual does not recomends it. does anyone know why? on the ser's sr20's, it was the stupid recirculaton crap and the injectors themselves that didn't like harsh chemicals and crap blowing around the egr stuff. what about the mazdas? i've looked a lil bit under the hood and it looks like alot of recirculation stuff? anyways, any troubles with throwing a bottle or two in?

btw, i was told not to do this often. so i do it every year or twice a yr, then change the oil soon afterwards.

thanks all.