Here the problem. Went out to take the stang to lunch today and it wont idle. It was fine on wed night when I parked it. When out today ....no idle. The exhaust sound different also it kinda pops louder at low RPM than usuall and once it warmed up it somewhat idled. But had a bad hesitation with justa little throttle. Also the vacume it low. If I coast with the clutch in and hit the brakes more than twice NO POWER BRAKES..you loose them. All the lines are ok. Could this be a bad sensor( I HOPE)? otherwise I'm thinking something in the valvetrain let loose. OH......i does run fine when you get on it. This ia all of a sudden to ...like I said it was fine on wed night. I'm going out to check everthing like TP voltage and aic motor and timing and the like. let me know what you think.