P0171 & P0174 4.0L SOHC's Sport/Sport Trac

[Ekim3897]

Auto Zone told me those codes, PO171 &174, would be associated with the mass air flow sensor and could just need a good cleaning of the sensors?? Any one with those problems?

 

[ncranchero]

Compared to the knowledge here AutoZone is lost! With that advice they need to stick to looking up parts on their computer and leave the diagnosis to those that know.

 

[Ekim3897]

I have already replaced the elbow but the engine light is still on and the codes PO171 & 174 came up.

 

[ncranchero]

Then it would more likely be an intake manifold leak.

Did you also inspect the rest of the PCV system? Dipstick seating properly?

 

[Ekim3897]

No I have not. Can you tell me about the PVC system. As you can tell, I am far from being a "mechanic".

 

[ncranchero]

The elbow you changed it the front elbow, and the most common to fail. that tube runs around the back of the engine to the PCV valve, which you need to make sure is clean and not stuck open. There is another elbow on the back side of that tube but I have never heard of it failing .......... yet.

This is the one you changed, right?

 

[MyTrac]

I just wanted to add...Also check the EGR valve, that was my problem at least. The little paper gaskets and such break down and ends up not sealing it right. Sometimes carbon gets caught up in there too and causes problems. I have found that carb cleaner is your best friend when looking for vacuum leaks! Just my 2 cents.

 

[Ekim3897]

Yes I changed the one in front. Where would the gasket leak be?

 

[MyTrac]

SO! When I sprayed carb cleaner around this area there was alot of reving (which means there is a leak) and so we took the thing apart! Come to find out the nuts were like tightened by fingers not a wrench!! Then we also found that the fabric like gasket had eroded away to nothing! So went to the autozone and bought a $2.60 gasket Put it on. THEN I put carb cleaner in the pod looking thing. THEN I turned the car on (Have someone with you) Rev the engine till its really screamin, and have your friend take the butt of a screwdriver and rap on that pod thing so that any carbon that built up in there would be released. Turn it off. Make sure all the connections are good and tight. Drive around for a little while and you should be good.

 

[KevXR]

I replaced the PCV hose elbow at the front of the engine with this part.
Napa heater hose elbow #7296 Under $7, plus two 1-/8 hose clamps at Napa.
I will replace it with the Ford OEM part after reading this other post.

Be careful using coolant hoses in the PCV system. If the hose you are replacing has direct contact with oil, oil vapors or gas, the hose will fall apart from the inside(leaving chunks or rubber falling into the engine). Coolant hoses are NOT PETROLEUM safe. You would need an emissions hose or fuel hose.

 

[KevXR]

2001 Ranger XLT 4.0 L

CEL came on. OBD2 reader said 0171 and 0174 errors.
Cleaned MAS
Replaced cracked PCV elbow hose.
Disconnected the battery. Left overnight.
Cleaned MAS again
Sprayed running engine with carb cleaner, no spikes in engine speed.
Drove about 18 miles on the freeway.

Still running a little rough.
OBD2 reader is showing:
Bank 1 Sensor 1 - Low and in range
Bank 2 Sensor 1 - Low and in range

Bank 1 Sensor 2 - STFT 99% O2S 0.79v
Is this bad? What would this indicate?

I am not seeing a Bank 2 Sensor 2. Is it my reader? Or does it not exist?

 

[pfree]

The elbow you changed it the front elbow, and the most common to fail. that tube runs around the back of the engine to the PCV valve, which you need to make sure is clean and not stuck open. There is another elbow on the back side of that tube but I have never heard of it failing .......... yet.

This is the one you changed, right?

I found a crack on the elbow and didn't feel like going to buy a new one so put duck tape over it and six months later still running great and no code..

 

[bubbasmida]

mine has a big rubber elbow on there and its not cracked plusits throwin po128

 

[hoorawflyguy]

NAPA Hose 9807 worked for me. $16

 

[05dakotatrac]

Ok for those of you that have issues with the 171-174 code and replacing the typical elbow doesn't fix it then your second issue might be the EVAP purge hose. the hose connects on the "vehicle left" side of the intake low underneath the EGR system. this hose runs 4" horizontal towards vehicle left then drops sown the side of the engine towards the header then back vehicle left to the fender where it connects to the purge solenoid. this stretch of hose tends to dry rot do to the excessive heat incurred by the EGR system and exhaust manifold being within inches of the hose. replacing this hose and wrapping in the exhaust manifold "heat tape" fixed my issue.

 

[wi_dude]

Thanks!

Just checked the elbow -- large crack on top. Just waiting till parts department opens...

 

[Esportxlt]

Thanks.
I had the same codes. Turns out the elbow was soft and cracked. Locale NAPA part 9807 $10.88

 

[Robnoctious]

WWasem I went out took off the plastic cover to the throttle body and there it was a cracked hose. Thanks for the great info. Hopefully that fixes my problem .

 

[Robnoctious]

I checked my hose and it was cracked. I went to napa auto and found a 5/8 id hose with a 90 degree bend. The hose was a little long but with a little trimming fit like a champ, price was good too 12$ So far it seemed to fix my problem. Thanks guys for all the great info.

 

[Drivem!]

There is a replacement hose in the "help" section of Autozone that I used. When you look at it it actually looks like it has more kink in it than needed but it worked perfect. $12. The package description was Dorman/PCV elbow...I believe it was # 46025.

Thank you to all for your input...this had been going on for awhile and it looks like it took care of our codes.

Drivem!