MAF Sensor

[Rob0424]

Is there any way to test if the MAF Sensor is bad? I recently have been getting the P0171 and P0174 codes and have already had the IAC valve replaced, the fuel filter replaced, the O2 sensors checked, the intake manifold gaskets replaced and the MAF sensor has been cleaned. The MAF sensor being broke is the only other thing I have read this code be. Any help? I just had the intake manifold gasket replaced like 3 weeks ago and the codes popped back up today.

 

[steve6534]

Is there any way to test if the MAF Sensor is bad? I recently have been getting the P0171 and P0174 codes and have already had the IAC valve replaced, the fuel filter replaced, the O2 sensors checked, the intake manifold gaskets replaced and the MAF sensor has been cleaned. The MAF sensor being broke is the only other thing I have read this code be. Any help? I just had the intake manifold gasket replaced like 3 weeks ago and the codes popped back up today.

The only real definitive way to see if the MAF is bad would be to hook up a scan tool and monitor the PID for the sensor. Short of that a vacuum leak from anywhere would cause those codes, it wouldn't necessarily be the intake gaskets although they are normally troublesome.

 

[Rob0424]

When I took it in and they fixed the intake gaskets they had hooked it up to a smoke machine so if there were any other leaks I would think they would have spotted those too. Is there any other thing anyone can thing of that would be throwing those codes, beside the MAF sensor being bad? Thanks

 

[NHale623]

I don't think the MAF is your problem. Did you check your fuel pressure?

 

[Rob0424]

No I have not done that yet. If I am not getting the correct fuel pressure what could the problem be?

 

[NHale623]

Low fuel pressure could be due to a plugged filter (you already changed that), a failed fuel pressure regulator, or a failing fuel pump.

You're running lean. You either have too much air or not enough fuel.

 

[Rob0424]

Ok, thanks for the suggestions. I am thinking of buying a new X before I go ahead and fix anything else on this one, so if I can't find any good deals I will look into those things.

 

[ñòóKýçrÕôK]

Short of that a vacuum leak from anywhere would cause those codes

Try spraying WD40 lightly around ends of vacuum hoses or even intake, throttle body edges. WD40 is heavier than air so when it hits a crack or leak while the engine is running it will fill the hole temporerilly and smooth out the engine. At least I think that's how it went last time I had a leaky intake on my old Ford Ranger that I used to have.

 

[Rob0424]

How big of an issue are these 2 codes? Is it something that I should definately make sure the problem is found and gets fixed?

 

[NHale623]

A lean engine runs hot.

Running lean may also lead to pre-ignition and/or detonation, which may cause damage to the pistons, heads, valves and spark plugs.

You also cannot pass an emissions inspection.

Bottom line, find and fix the problem.

 

[Medic 19]

I don't mean to hijack your thread but I have also thrown those codes. The kicker is that the engine only does something funny when it is overnight cold and the colder it is outside the more it will want to die. This will last for less than a minute but I do have to keep giving it throttle or it will stall. If I reset the ecu I may not get another ce light until it is really cold (for a Californian) 45-50* but it will continue to want to die when cold. The first time it did this and threw the codes was during a winter storm in the Sierras last year. It's a 2k with only 55k mi. During the spring, summer, and fall it ran fine and threw no codes. It really seems to me that some temp sensor is failing rather than a vacuum leak. Any help would be appreciated. Brent

 

[NHale623]

The intake gaskets are o-rings. They harden with age, and they shrink when they get cold. Hard idle on cold mornings combined with codes P0171 and P0174 are classic symptoms of failed intake gaskets.

 

[Vinniety]

Try spraying WD40 lightly around ends of vacuum hoses or even intake, throttle body edges. WD40 is heavier than air so when it hits a crack or leak while the engine is running it will fill the hole temporerilly and smooth out the engine. At least I think that's how it went last time I had a leaky intake on my old Ford Ranger that I used to have.

Use carb cleaner instead of WD40 it will work better. Spray the hell out of the motor around every intake gasket, line anything and everything. I would recommend to do it once it is cold. Start it open the hood and spray like crazy. If you do it when its hot you can cause a fire becasue the cleaner is flammable but i have done it before when its hot and just taken it easier then if the motor was cold.

I am in the same situation. These stupid codes. I sprayed the hell out of my motor and no leaks. I changed the pcv valve last night and going to do the gas filter hoepefully tonight. I also did seafoam and cleaned out the intake VERY good. Sprayed the hell out of it.


Reset the light last night so im going to give it a few days and see if i get lucky to pass inspection.

 

[joe doe]

i dont know what engine you guys have but my 2000 ex sport with ohv engine 4.0 was throwing these codes for quite awhile .after reading everything i could i went and had the job done .what you are replacing here isnt the intake manifold gaskets but actually the upper intake plenum orings ....if you have a iron/steel lower intake those arent the gaskets to replace.you want the upper intake plenum orings ..thats what leaks ...i tried the spray can around the intake trick too and nothing showed up.but it was definitly those orings .......i also replaced the fuel rail gasket...because you have to break that seal to get the upper off ..so buy that too.different years use different upper orings and fuel rail gaskets ..so be sure to check that.laboar was about 120.00 plus parts and my light has been off a couple months now ....and its been cold here...


oh hey medic ..i read about a tsb on this and if you have under 72k miles or 7 years whichever comes first ..if you fall under that i hear ford will fix it free.just make some noise about a tsb on the problem ,you having only 55k miles ect.....might get ya a free fix if you act fast .check the door sticker date.that goes for anyone with this problem that have under 72k and 7 years ....i found out 20,000 miles too late