Because of a destroyed hose between the sensor and the filterbox, I had my car running without these items for a month or so. I can't say that the car ran smoothly without the flow sensor. Now that I hooked up the stove connection and the remaining hose to the filter unit, it feels that the car runs better. Somebody had told me earlier that in hot weather, this hot/cold air mixture apparatus is useless. Have an opinion? Let me know what you think. JohnE 10250