My EHA valve was leaking through the plastic case. I put a new one on and have been trying to get it adjusted right. When I get it to idle very smooth it gets awful MPG. Like 13! I check my Duty cycle it is around 55-60. To get good milage on the highway it idles with a drop and stumbles on light acceleration. I have new plugs cap and rotor are very good timing is on the money. Plugs are factory specs not the Zone specials. It also has a new Idle control vale and hoses. Thanks Alan