p0101 and p0463

My brother has a 02 chevy s10 with the 4.3 v6. It can hardly drive now. It is so boggy and will only accalerate up to about 3200 RMP and doesnt shift unless you let off the gas. And the longer you drive it the slower it will get. Starting off going about 50 after 5-10 minutes only about 25-30. and the RPM wont go as high.

hooked up a code reader and got 2 p0101 codes. And then when i go into the enhanced DTC's i get the p0463 code which is probably why the gas gauge is all the way to empty even though it has gas.

The P0101 means this:
What does that mean?


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.

Symptoms


You will likely not notice any serious drivability problems, although there may be symptoms.

Possible Solutions


The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:

• <li itxtHarvested="0" itxtNodeId="54">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 <li itxtHarvested="0" itxtNodeId="53">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. <li itxtHarvested="0" itxtNodeId="52">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. <li itxtHarvested="0" itxtNodeId="51">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. <li itxtHarvested="0" itxtNodeId="50">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. <li itxtHarvested="0" itxtNodeId="49">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.

We replaced the Mass Air Flow Sensor and it was doing the same thing.
We replaced the MAP sensor and doing the same thing.
We checked the voltage to both sensors and both had the right voltage. Doesnt appear to have any leaks in the air stream and the PCV looks good.

Here is the Freeze Frame Data from the p0101 code:
Fuel System 1- CL
Fuel System 2- CL
Calc Load(%)- 37.65
ETC(degree C)- 90
STFT B1(%)- 7.03
LTFT B1(%)- 1.56
STFT B2(%)- 11.72
LTFT B2(%)- 0.00
MAP(kPa)- 97.00
Engine RPM- 2516
Veh Speed(km/h)- 52
MAF(g/s)- 63.21
TPS(%)- 64.71

Is it possible we got a bad mass air flow sensor from the auto parts store? Could it be both the mass air flow and fuel pump? Bad intake manifold gasket? Any help would be greatly appreciated. Thanks...mike

 

I used to own a S-10 with a 4.3, before I got my Taco. My book recommends you check the PCV valve and the hose to see if it stopped up. A restricted exhaust will cause a bad MAF code to trigger also. You need to see if the Catlytic converter is clogged up and restricting the exhaust. This may account for the loss of performance , the longer you run it.I would look for a hot or glowing converter while it is running. You could be having PCM or computer problems also. I hope this helps. Good Luck.

 

Good post by tacoguy. My first thought was a clogged cat too. Never would have believed it possible if I hadn't seen it in person before. Just like the OP described, except that was a few years before cars had diags that gave codes.

ETA: I think that the only thing that could cause those symptoms would be the clogged cat or ignition timing way off, like vacuum advance not working. Old school thoughts here though...

 

Thanks for the replys guys. It did have a funny smell after driving it for a while. maybe from the clogged cat? I guess we will drive it at night for a while and see if we can see if its the cats. Would cats be a red or orange color?

And does anybody know if the freeze frame data seems to look good. Thanks again