MAF Sensors Purpose

[Leon3]

What exactly is the function of the MAF sensor ? Does it wire straight to the the computer or does it send signals to another car conponent ? Lastly how would its malfunction cause a miss on 246 ? Just curious but serious.

Thanks in advance

[wildrage]

The Mass Airflow Sensor meters the air coming into the engine in order to determine the fuel/air ratio. When they go bad or are dirty they generally cause rough idling, sluggish acceleration, or missfiring on all or random cylinders. If you are consistantly getting a miss on a particular cylinder you should look more towards the plug or coil/wire (depending on your year).

[Cadi Cat]

I have a question. What's the difference between the Mass Air-Flow Sensor vs the Mass Air Sensor?

[Warez]

Originally Posted by Cadi Cat

I have a question. What's the difference between the Mass Air-Flow Sensor vs the Mass Air Sensor?

Same thing.

[ewill3rd]

The MAF or "Mass Air Flow" sensor measures the actual volume of air entering the engine for combustion.

Basically a sense wire is placed in the flow of air and using one of a couple methods a small processor calculates the airflow and sends a signal back to the engine controller. The ECM then uses other sensors to calculate the required amount of fuel needed for the conditions being measured by things like the MAP (intake pressure) sensor, engine coolant temperature, calculated load, current gear selection, throttle position, etc...

What happens typically on Catera is that when the MAF fails it will give false readings.
If the MAF is lying to the ECM the ECM will think it is getting more or less air than it actually is, this causes an imbalance in the air/fuel ratio and the engine runs lean or rich. Sometimes this will have more of an effect on one bank or the other with that engine.
I have seen big issues with failing MAF sensors on Catera that cause all sorts of misfires and drivability problems.

Some manufacturers have slightly different names for sensors but GM has always called it a MAF sensor.

[Army_MP_From_MO]

I love it when a Cadillac Technician visits our threads.

[pghjoe]

How difficult is this part to change on your own???

[ewill3rd]

Most MAF sensors are fairly easy to replace.
Some just have two hose clamps holding them in place in the air stream, some are 2 or three screws holding them on an assembly.
Some older ones are built into the airbox (and some new ones too).

Catera has one that is fairly easy to access, it is over to the right side of the car in the ductwork.
Pretty easy to replace once you get some of the ductwork out of the way.

[pghjoe]

How would someone get information on how to change this and other parts of the car?

[ewill3rd]

A factory service manual "FSM" is a good place to start, although sometimes it is easier to figure it out yourself than it is to look it up in the manual.

I think there might be some information scattered about the forums, using the "search" function might get you some good results.
The FAQ often has a lot of good info in it although not sure about Catera stuff.
If all else fails just start a post and ask.

If you get the part and look at it and then look at your car to find it you should be able to see how it is installed and pretty much see how you can change it out.
If you still have problems most independent shops would be willing to toss parts on for a few bucks but don't look to them to guarantee that it will fix the problem.