98 chevy suburban, code reads mass air flow sensor low input. whats the problem? i have replaced the mass air flow sensor twice and i have no vacum leaks.

Do yourself a favor an take it to a qualified repair shop . We can't help you with that little bit of info. Why can't you get it to work right , how do you know it's not , what's scan data show ? Electrical circuit's good ? Code's stored for MAF sensor ?

Hi Chris.

p0304 = Number 4 Cylinder Misfire Detected

Faulty spark plug 4
Clogged or faulty fuel injector 4
Faulty ignition coil 4
Fuel injector 4 harness is open or shorted
Fuel injector 4 circuit poor electrical connection
Ignition coil 4 harness is open or shorted
Ignition coil 4 circuit poor electrical connection
Insufficient cylinder 4 compression
Incorrect fuel pressure
Intake air leak

The P0304 code means that the cylinder 4 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 4.


p0102 = Mass or Volume Air Flow Circuit Low Input

Faulty mass air flow sensor
Intake air leaks
Dirty mass air flow sensor
Dirty mass air filter
Mass air flow sensor harness is open or shorted
Mass air flow sensor circuit poor electrical connection

Before replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner.
Reset code and drive vehicle.
If the code comes back, it may be necessary to replaced the mass air flow sensor.


p0154 = O2 Sensor Circuit No Activity Detected Sensor 1 Bank 2

Faulty Front Heated Oxygen Sensor Bank 2
Front Heated Oxygen Sensor Bank 2 harness is open or shorted
Front Heated Oxygen Sensor Bank 2 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

Replacing the Front Heated Oxygen Sensor Bank 2 usually takes care of the problem.


p0113 = Intake Air Temperature Sensor Circuit High

Faulty Intake Air Temperature (IAT) sensor
Dirty air filter
Intake Air Temperature (IAT) sensor harness is open or shorted
Intake Air Temperature (IAT) sensor circuit poor electrical connection

The Intake Air Temperature (IAT) sensor is built into mass air flow sensor or in some vehicles mounted to the air filter duct housing. The sensor detects intake air temperature and transmits a signal to the Engine Control Module (ECM).The temperature sensing unit uses a thermistor which is sensitive to the change in temperature. Electrical resistance of the thermistor decreases in response to the temperature rise. The Intake Air Temperature signal is used as an input for various systems in the vehicle.



Hope this helps
FYT

http://www.autocodes.com/make/nissan

code p 0102 refers to mass air flow(MAF) sensor /volume air flow (VAF) sensor --low input===causes --wiring short to ground ---MAF/VAF sensor ---ECM
check wiring for insulation problems or broken connections
replace the MAF sensor

ok lets start with the codes they say your getting. P??? which 1's and how many. there are few o2 sensors, are they next to the Exhaust next to the converter? MASS AIR FLOW -MAF use this, for now i am guessing, until i see the correct codes your are getting. this could be the 1 you may have below, please read it........

• P0103
  Mass Air Flow Sensor Circuit High Input
• Possible causes
• Faulty mass air flow sensor
  - Intake air leaks
  - Dirty mass air flow sensor
  - Dirty mass air filter
  - Mass air flow sensor harness is open or shorted
  - Mass air flow sensor circuit poor electrical connection
• Before replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner. Reset code and drive vehicle. If the code comes back, it may be necessary to replaced the mass air flow sensor.
• possible symptoms Engine Light ON (or Service Engine Soon Warning Light)
  - Engine stall
  - Engine running rough
  - Excessive fuel consumption
  - Excessive smoke
• the code is generated when An excessively high voltage from the sensor is sent to Engine Control Module (ECM).

2003 NISSAN Altima Sedan OBDII Codes List

P0102 Chevrolet - Mass or Volume Air Flow Circuit Low Input

Read more: http://engine-codes.com/p0102_chevrolet.html#ixzz38p5k1ZD8

Possible causes - Faulty mass air flow sensor
- Intake air leaks
- Dirty mass air flow sensor
- Dirty mass air filter
- Mass air flow sensor harness is open or shorted
- Mass air flow sensor circuit poor electrical connection

Before replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner. Reset code and drive vehicle. If the code comes back, it may be necessary to replaced the mass air flow sensor.


Read more: http://engine-codes.com/p0102_chevrolet.html#ixzz38p5tpWZk

code 23 is MAT too low.(mass air temp.) code 36 is Mass Air Flow Sensor Error

The ECM receives a signal from the Mass Air Flow sensor depending on the amount of air entering the engine. The ECM uses information from this sensor to help calculate fuel delivery and spark timing.

Fault Code Description

• 36 - Mass Air Flow sensor error

Symptoms

• Engine stalling
• Lack of power

Common Problems Faulty Mass Air Flow sensor,Broken wire to Mass Air Flow sensor,Dirty sensing element in Mass Air Flow sensor

the code 113 is intake air temp cicuit, high input.
the code 102 is mass air flow volume air flow circuit, low input.
the code 171 is system too lean (bank 1)
I sure hope this helps you out. Dont sound like anything too major though

FIRST CHECK FUEL PREASURE (I THINK ABOUT 3,3 BAR).IF OK, CHANGE AIR FLOW SENSOR.
MARKO

Hi. this code represents an issue within the mass air flow sensor. it is malfunctioning at this point. the mass air flow sensor Measures the volume and density of air entering the engine, so the electronic control module can determine how much fuel is needed to maintain the correct air to fuel mixture. There are two basic types: heated wire and heated film (grid); both work on the same principle.

A faulty MAF will cause driveability problems resulting from incorrect ignition timing and improper air/fuel ratios.

this device is located Under hood, center, upper engine area, mounted on rear of air intake duct


To replace a MAF sensor:

• Locate the sensor.
• Disconnect the negative battery cable.
• Unplug the wiring harness and vacuum hose.
• Unscrew the two screws holding the sensor in place.
• Reverse the procedures to install a new sensor.

Please rate and god bless:)

did it have the same code before you change the 02 sensor .cause it should of been po135 for an 02 sensor 1 bank .the mass is the one in the air breather