I have a 2001 Ford Focus with 150,000 miles. I have replaced the fuel pump, fuel filter, spark plugs and wires, pvc valve, air filter, changed the oil, bought a new MAF sensor and the car still runs like crap. I had the check engine light code read at auto zone and it read; P0102 – - low voltage / low frequency to Mass Airflow Sensor. The car will idle and run normal about half the time. But the other half of the time I have to hold the brake with one foot and keep my other foot on the gas pedal just to keep it from stalling. Then when I go to take off at the light it will hesitate extremely bad for about 5-10 seconds before it will take off. Car runs and drives fine when out on the highway.
I don’t know if this makes a difference but the cooling fan seems to kick on a lot (car does not overheat). Whenever the fan kicks on or A/C compressor is running the car runs worse. Any ideas???