gryps

i ran the ecu diagnostics and i got two error codes:

04 01 Intake Air Temp Sensor
01 02 Mass Air Flow Sensor



how do i check/replace these sensors?

i have a stillen cai and i think the maf sensor is attached to the end of the k&n filter?


i have a 96 se 5spd with 85K

Jamsan

iTrader: (2)

stillen makes a cai

about your codes, make sure everyone is connected, no leaks, all sensors plugged in...i believe you have to plug in one of the sensors (forgot the actual one) somewhere into the stillen intake

gryps

meant to say stillen high flow intake

is the maf attached to the end of the k&n filter

gryps

could these fault codes cause low end power loss?

iwannabmw

iTrader: (3)

The intake air sensor is usually installed into the end of the cone intake when people put it on. The MAF is the is the one that is right next to the filter as you start heading towards the engine. It sticks out of the side of the housing. You should make sure that connection is tight. The MAF can cause major driveability problems.

gryps

another newbie question:

is calibration/adjustment required when replacing those sensors?

iwannabmw

iTrader: (3)

Pretty much plug and play. For faster results, reset the ECU after.

Jamsan

iTrader: (2)

its not the fault codes themself.....the pop charger is what causes the power loss....make or buy, the upper intake portion, and your low end power *should* return

meccanoble

iTrader: (22)

my air temp sensor came on (4 1) cause i installed CAI and didn't plug in air temp sensor. I had intake of a wrong year (97 and up) and they don't have this harness. I just took out harness from stock intake, plugged it and rolled it up somewhere under the hood. If yours isn't plugged in try this. I resetted the ECU and my light has been gone since.

bill99gxe

iTrader: (1)

Search results:


"0401"

DTC 0401

Diagnostic Trouble Code 0401 points to a problem with the Intake Air Temperature Sensor.

The IATS is mounted in the engine air intake duct, downstream of the air cleaner filter. It detects intake air temperature and transmits a signal to the Engine Control Module. The sensor uses a thermistor, a resistor with a value which is inversely proportional to temperature. The IATS is not directly used to control the engine. It is used only for diagnostic purposes. Therefore the engine should start and run normally, even with the Malfunction Indicator
Light on and DTC 0401 stored.

This malfunction is detected when ...

a) An excessively low or high voltage from the sensor is detected by the ECM.
b) The signal from the IATS is inconsistent with the signal received from the Engine Coolant Temperature Sensor.

Possible causes include ...
- Harness or connectors (The sensor circuit is open or shorted.)
- a faulty Intake Air Temperature Sensor

The IATS resistance values should be ...
- at 14 degrees F, 7.0-11.4 Kohms
- at 68 degrees F, 2.1-2.9 Kohms
- at 176 degrees F, 0.27-0.38 Kohms

For further information about the Intake Air Temperature Sensor please refer to the Chilton repair manual (page
4-16) or the Haynes repair manual (page 6-11).


"0102"

DTC 0102

Diagnostic Trouble Code 0102 points to a problem with the Mass Air Flow Sensor.

The MAFS is placed in the stream of intake air. It measures the intake flow rate by measuring a part of the entire intake flow. It consists of a thin film that is supplied with electric current from the Engine Control Module. The temperature of the hot film is controlled by the ECM a certain amount. The heat generated by the hot wire is reduced as the intake air flows around it. The more air, the greater the heat loss. Therefore, the ECM must supply more electric current to the hot film as air flow increases. This maintains the temperature of the hot film. The ECM detects the air flow by means of this current change.

This malfunction is detected when an out-of-range voltage is sent to the ECM. That voltage might be too high
or too low.

a) An excessively high voltage from the MAFS is sent when the engine is not running.
b) An excessively high voltage from the MAFS is sent under light load driving conditions.

Possible causes include...
- Harness or connectors (the sensor circuit is open or shorted.)
- Faulty MAFS

c) An excessively low voltage from the MAFS is sent when the engine is not running.
d) An excessively low voltage from the MAFS is sent under heavy load driving conditions.

Possible causes include...
- Harness or connectors (the sensor circuit is open or shorted.)
- Intake air leaks
- Faulty MAFS

With DTC 0102 the ECM is supposed to switch into Fail Safe mode and limit engine speed to 2400 rpm.

gryps

i have reset the ecu and the codes didn't come back i also changed the fuel filter and cleaned the tb

what else should i check my low end torque really sucks and the idle speed is high ~900rpm

bill99gxe

iTrader: (1)

Drive a few days.....the codes should come back.

iwannabmw

iTrader: (3)

Well, the idle speed is probably related to the now clean TB. That's easy to adjust. Like Bill said, the codes will probably come back in a few days. If the connections to the two sensors are tight, and you still get the MAF one, my bet is that it was damaged during the install. Like I mentioned before, the MAF sensor can cause serious driveability issues and may be related to your torque issue, assuming that's not just the typical "problem" associated with these intakes.

gryps

i bought the car with the stillen intake already installed. the loss of low end problem first started last summer when the car would ocasionally stall in idle (once in the middle of the turn while i was downshifting). i took the car to the dealership and had a tune up done and that seemed to fix it a little. now the problem is back and i'm thinking of taking it back to the dealership but i would rather fix it myself (or at least find out what's wrong).

thanx for your help so far

Jamsan

iTrader: (2)

seems like an IAC valve problem.....first check to see of the hoses are loose or leaking...then clean out the unit itself....do a search on how to