I have a driveablility issue with my '02 Z06 that I need help with. When cruising around at steady RPM I get a momentary buck/loss of power/mis type thing happening every so often. Sometimes it happens a lot and sometimes a little bit. A little history..the previous owner installed a Granetelli MAF and a HYpertech PP III. I swapped out the MAF back to stock(owner gave it to me) and that did not help. Today I went to take the Hypertech programming out but it said I had a code. The code was:
P0101 Mass Air Flow (MAF) System Performance. I cleared the code and took the programming out of the car but that still did not solve it. Does anyone have any ideas as to what could be causing my driveability issue? I was thinking about buying a new MAF sensor to see if that helped.
Thanks in advance!

 

Wild guess here but you might want to double check all of your harness grounds: http://forums.corvetteforum.com/showthread.php?t=896875 .

Northern tier cars have it rough in this department sometimes.

Hope you find the problem.

 

Anything else done to the car...cam? heads? s/c?


I got this code consistently after my cam install. I had to up the "MAF Rationality Test" table in EFI-Live to clear it.

If you have no major power adders, then I'd guess something is still not right with the MAF.

 

Other mods are a Blackwing and Borla Cat back, so nothing major at all. Also, the car runs great at full throttle.

 

I didn't mention that my fan shroud is cut to let more air into the Blackwing. After doing further research it seems that many people who cut the shroud and have the blackwing get this problem. May be time for the Vararam.

 

Yeah, sounds like an issue they used to call fan wash in the 5.0 stangs....using an open element air filter on those cars would cause idle surge once the fans came on as they 'washed' the air going into the filter, thus skewing the readings at the MAF. The only real solution, was to put the filter in an enclosure or in the fender.

I'd say go for the Vararam, you cant miss with it.

Good luck.

 

Interesting

BTW.....Great Avatar

 

Do you know if the previous owner re-calibrated your MAF table and flashed it into your ECM so that the granatelli had "0" LTFT's ??-If so--after putting your stock MAF back in--your table could be messed up-- Need to check and see if the stock MAF table is in your ECM -You can get a copy of the stock program from holdencrazy---Also--i would still log your stock MAF to get your LTFT's in line just to be sure---

 

Had the same problem with mine(101,171,174) Previous owner had cut a rectangular opening in the shroud about 3"X9". That combined with the Blackwing creates some air flow issues that the MAF does not like, especially on deceleration. Try some duct tape over the hole as an experiment and I'll bet your code 101 problem will go away

Steve

 

DTC P0101
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The powertrain control module (PCM) uses the MAF sensor signal in order to provide the correct fuel delivery for a wide range of engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle. A large quantity of air entering the engine indicates an acceleration or high load condition. The MAF sensor has an ignition 1 voltage circuit, a ground circuit and a signal circuit. The PCM applies a voltage to the sensor on the signal circuit. The sensor uses the voltage in order to produce a frequency based on inlet air flow through the sensor bore. The frequency varies within a range of around 2,000 Hertz at idle to about 11,500 Hertz at maximum engine load. The PCM uses the following sensor inputs in order to calculate a predicted MAF value:

The manifold absolute pressure (MAP)
The intake air temperature (IAT)
The engine coolant temperature (ECT)
The engine speed (RPM)
The PCM compares the actual MAF sensor frequency signal to the predicted MAF value. This comparison will determine if the signal is stuck based on a lack of variation, or is too low or too high for a given operating condition. DTC P0101 sets if the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value.

Conditions for Running the DTC
DTCs P0102, P0103, P0107, P0108, P0112, P0113, P1120, P1220, and P1221 are not set.
The engine is running.
The ignition 1 signal is between 11-18 volts.
The throttle position (TP) indicated angle is less than 95 percent.
The change in the TP indicated angle is less than 5 percent.
The MAP sensor is more than 17 kPa.
The change in the MAP sensor is less than 3 kPa.
The above conditions are met for 1.5 seconds.
Conditions for Setting the DTC
The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 0.5 second.

Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
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
Any excessive deposits on the throttle plate or in the throttle bore.
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 acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 4-7 g/s at idle to 190 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 that is used in order to calculate the predicted mass air flow value is initially based on the MAP sensor at key ON. When the engine is running the MAP sensor value is continually updated near wide open throttle. A skewed MAP sensor will cause the calculated mass air flow 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.