Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Cant fix P0101 mass air flow sensor


Hi I have a 2003 kia rio 1.6 dohc with 130,000 miles on it all maintenance is up to date I got a code p0101 i put on 3 mass air flow sensors 2 from a local auto parts store the 1 the last one from the dealer cleared the code it comes back I changed the tps and cleared the code it still comes backs. It has a new air filter and I cant find any vacuum leaks. right before the code sets the will be a slight hesitation on take off not every time but a few times during a ride. Then the light will be set if i clear the code the hesitation will go away but when it comes back then the code p0101 sets.

Please help me i have tried everything.


Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4.0 seconds. Other MAF sensor circuit DTC trouble codes are P0100, P0102, P0103, and P0104.Inspect for the following conditions:
An incorrectly routed harness–Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components:

  • The secondary ignition wires or coils
  • Any solenoids
  • Any relays
  • Any motors
    A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
    A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 6-12 g/s at idle to 230 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
    The barometric pressure (BARO) that is used in order to calculate the predicted MAF value is initially based on the MAP sensor at key ON.
    When the engine is running the MAP sensor value is continually updated near WOT. A skewed MAP sensor will cause the calculated MAF value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
    A high resistance on the ground circuit of the MAP sensor can cause this DTC to set.
    Any loss of vacuum to the MAP sensor can cause this DTC to set.
    I hope this helps. I recommend you see an independent mechanic as the dealership is the last place to go for repairs.

There is a video to go with the info that missleman gave you:
Look for vacuum leaks from things the vacuum hoses attach to (power brake booster, cruise control, pcv valve, EGR valve, charcoal canister, EVAP system.
With the engine running, pull the vacuum hoses, one at a time, and plug its port to the intake manifold. Note any change in how the engine runs. When you pull and plug one, and the engine runs better, check the vacuum holding ability of that component (for example, the brake booster).
Check the large black intake tube for splits, and make sure that it is sealing where it connects to the throttle body.