Brake Pedal is Soft then hard brake, have a P0171 " too lean condition " that I have been trying to figure out with multiple mechanics, ughhh.... checked all my calipers, lines, bleeding the system did help for a little..improved brake pedal response.. trying to cover basics before I get to the brake booster or master $$$$$ only 115,000 miles on it , thinking maybe the check valve isn't working properly, but since its in the line, cann't blow in it
