Solved P0171 & P0174 codes.

[Anabolic3xploder]

truck showed codes P0171 , system too lean , P0174 , system too lean. bank 1 and 2..... does anyone know what this means or have had the same issue? guy told me it was the oxygen sensors. thank you for your time.

jeff

 

[BrooklynBay]

Check the intake manifold gaskets, and the vacuum lines for leaks.

 

[LONO100]

If you have the sohc, go into the 01-05 sport trac section and look for the sticky titled with those codes. This is most likely causing the codes and its a very simple fix. Good luck!

 

[ssobel80]

+1 on the intake manifold gaskets

 

[TwiztidRat]

Intake manifold gaskets, I just had to replace those on my truck.

 

[R1dd1cK]

I have the same 2 codes but I have the v8.

 

[Anabolic3xploder]

i contacted the local ford dealer and this is what they said: The O2 sensors for your Explorer are # F88Z 9F472 BA on the passenger side, F88Z 9F472 CA on the drivers side. Around $60 each and I can have them overnite. But..there could be an underlying reason those sensors failed. Possible they're bad because of high mileage but intake gasket leaks will cause O2 sensor failures also.Very common on your 4.0 Explorer.So,if you put new sensors in they could fail again within 100 miles. so, you may want to investigate further, anything's possible..You can always plug in the above numbers in Fordpart.com/and order them anytime.. Hope this helps,

 

[swshawaii]

Which engine? Last thing you want is to change expensive, non returnable parts without a fix. If SOHC:

http://www.explorerforum.com/forums/showthread.php?p=2364255

 

[Anabolic3xploder]

1998 , 4.0l sohc. cleaned the MAF sensor earlier and it idles great now. cleaned it before and it did great for a few days and then it was back to the a fluctuating idle. i will see what happens in the next few days

 

[DeepEmissions]

1998 , 4.0l sohc. cleaned the MAF sensor earlier and it idles great now. cleaned it before and it did great for a few days and then it was back to the a fluctuating idle. i will see what happens in the next few days

I did the exact same thing because of these codes, cleaned MAF all the way up to the TB, was great for a few days then the rough idle returned. I also did SeaFoam at the same time.
I'll be checking my intake manifold gaskets as well. Good Luck.

 

[Anabolic3xploder]

got the upper and lower intake gaskets on this morning and the explorer is purring like a kitten. thank you guys

 

[BrooklynBay]

Thanks for the update! I'm going to mark this thread as solved.

 

[Chris1973]

truck showed codes P0171 , system too lean , P0174 , system too lean. bank 1 and 2..... does anyone know what this means or have had the same issue? guy told me it was the oxygen sensors. thank you for your time

truck showed codes P0171 , system too lean , P0174 , system too lean. bank 1 and 2..... does anyone know what this means or have had the same issue? guy told me it was the oxygen sensors. thank you for your time.

jeff

Had the same codes a couple of months ago. It was the camshaft sensor. And I also while doing that change the crankshaft sensor and the map sensor. Might as well do all three they're all interconnected and it worked perfectly.

 

[410Fortune]

wrong
The cam sensor and the crank sensor are not connected
There is no MAP sensor
Crankshaft sensor is used for starting (crank trigger)
Camshaft sensor is used for timing (cam timing)

MAP sensor is Manifold Absolute Pressure, a MAP sensor is fed by a vacuum line
The last year of a MAP sensor in these trucks was the 2.9L engine in 1990
The 4.0 OHV or SOHC NEVER had a map sensor

171 and 174 are air leaks, it means lean both banks
This means the computer has noticed a lean condition it cannot dump enough fuel to correct. It has seen it enough times/enough drive cycles to set the code. Usually (like 99% of the time) this is air entering the intake manifold that was not metered or measured by the mass air flow sensor (un metered air)
un metered air entering the system after the MAS sensor (mas air flow sensor) and before the 02 sensors............ on the 4.0 V6 engine it is almost always intake gasket O rings, as stated earlier in this SOLVED thread from 2013 (9 years ago)
The other possible cause would be a large air leak in the intake tube, EGR system, or a large crack in the intake. Air entering the intake that was not accounted for.
By swapping the crank, cam and I assume MAS sensors you likely fixed a large air leak in your intake tube OR the codes will return
I hope this helps! This is like the 3rd 10+ year old thread regarding 171 and 174 codes you have revived

 

[MuscleJunkie]

Also check your injector connectors

 

[Chris1973]

wrong
The cam sensor and the crank sensor are not connected
There is no MAP sensor
Crankshaft sensor is used for starting (crank trigger)
Camshaft sensor is used for timing (cam timing)

MAP sensor is Manifold Absolute Pressure, a MAP sensor is fed by a vacuum line
The last year of a MAP sensor in these trucks was the 2.9L engine in 1990
The 4.0 OHV or SOHC NEVER had a map sensor

171 and 174 are air leaks, it means lean both banks
This means the computer has noticed a lean condition it cannot dump enough fuel to correct. It has seen it enough times/enough drive cycles to set the code. Usually (like 99% of the time) this is air entering the intake manifold that was not metered or measured by the mass air flow sensor (un metered air)
un metered air entering the system after the MAS sensor (mas air flow sensor) and before the 02 sensors............ on the 4.0 V6 engine it is almost always intake gasket O rings, as stated earlier in this SOLVED thread from 2013 (9 years ago)
The other possible cause would be a large air leak in the intake tube, EGR system, or a large crack in the intake. Air entering the intake that was not accounted for.
By swapping the crank, cam and I assume MAS sensors you likely fixed a large air leak in your intake tube OR the codes will return
I hope this helps! This is like the 3rd 10+ year old thread regarding 171 and 174 codes you have revived

So I had both codes on a 2000 with the 302 v-8 and changed the camshaft sensor and codes gone running perfect.

 

[Chris1973]

wrong
The cam sensor and the crank sensor are not connected
There is no MAP sensor
Crankshaft sensor is used for starting (crank trigger)
Camshaft sensor is used for timing (cam timing)

MAP sensor is Manifold Absolute Pressure, a MAP sensor is fed by a vacuum line
The last year of a MAP sensor in these trucks was the 2.9L engine in 1990
The 4.0 OHV or SOHC NEVER had a map sensor

171 and 174 are air leaks, it means lean both banks
This means the computer has noticed a lean condition it cannot dump enough fuel to correct. It has seen it enough times/enough drive cycles to set the code. Usually (like 99% of the time) this is air entering the intake manifold that was not metered or measured by the mass air flow sensor (un metered air)
un metered air entering the system after the MAS sensor (mas air flow sensor) and before the 02 sensors............ on the 4.0 V6 engine it is almost always intake gasket O rings, as stated earlier in this SOLVED thread from 2013 (9 years ago)
The other possible cause would be a large air leak in the intake tube, EGR system, or a large crack in the intake. Air entering the intake that was not accounted for.
By swapping the crank, cam and I assume MAS sensors you likely fixed a large air leak in your intake tube OR the codes will return
I hope this helps! This is like the 3rd 10+ year old thread regarding 171 and 174 codes you have revived

And I was told by Ford that those 2 codes at the same time always in the 302 is the map sensor or the camshaft or crankshaft sensor.they said that's what the ecu See's it as.

 

[410Fortune]

Ford told you the 171 and 174 are the MAP sensor on the 5.0?

WHAT MAP SENSOR
Ford who? Some parts desk jockey? Did you pay for diagnosis?
If you have a 5.0 truck why are you posting about 171 and 174 codes in the v6 threads?

The 5.0 also has an intake, it also has EGR, 171 and 174 are AIR LEAKS effecting both banks no matter what engine

GOOGLE P0171 and P0174 see if the CAM, CRANK or non existent MAP sensors are mentioned

 

[Chris1973]

Ford told you the 171 and 174 are the MAP sensor on the 5.0?

WHAT MAP SENSOR
Ford who? Some parts desk jockey? Did you pay for diagnosis?
If you have a 5.0 truck why are you posting about 171 and 174 codes in the v6 threads?

The 5.0 also has an intake, it also has EGR, 171 and 174 are AIR LEAKS effecting both banks no matter what engine

GOOGLE P0171 and P0174 see if the CAM, CRANK or non existent MAP sensors are mentioned

Not google.both codes.would barely start and ran like it was missing cylinders.camshaft sensor replaced and back to normal.

 

[Chris1973]

Not google.both codes.would barely start and ran like it was missing cylinders.camshaft sensor replaced and back to normal.

They didn't say I just said map instead of maf and the main people I got the info from were on this site.and they were dead on right.and I didn't realize it was a v-6 until you said it.my fault.