dtc 171 174

2000 ford windstar 3.8L- 50,000 miles bought used no warranty. check engine light came on today. Went to local autozone and the codes po171 and po174 came up. They told me that it was running lean in bank 1 and 2. couldn't get much info from them. So went online and noticed all the comments on replacing leaking manifold gaskets and bolts,etc. not sure if that is the problem, but the Ford dealer wanted 100.00 for a diagnostic check. Not sure if it is worth it? or is it a waste of time. or should I just replace the gaskets and bolts,etc. don't know what to do next because I have been told it could be anything from changing the spark plugs to the fuel filter and the o2 sensor along with the vacuum hoses. PLEASE HELP!!!!

171/174 indicates a lean condition on both banks 1 and 2. A lean condition normally occurs when air enters the system after the MAF (the device that measures airflow). In other words the PCM "thinks" there is a certain volume of air and adds the appropriate amount of fuel and then the O2 sensor reads lean after combustion.

Causes include:
- MAF not reading correctly. Could be defective or dirty.
- Fuel flow problem
- Vacuum leak.
- Bad O2 sensor

I would not suspect the O2 sensor although they seem to get blamed more often than they should.
A MAF sensor theoretically can be cleaned. Fuel flow would probably affect drivability.

More than likely you have a vacuum leak. It is hard to pinpoint an intake leak but you could ensure that no hoses are loose. The infamous Isolator bolt leak is a good candidate and if you have no other drivability concerns that will probably be what Ford recommends after you pay the $100 for them to read the codes.

to DRW1000: thank you for replying. most likely I will have to replace the bolts.

Go threw what DRW1000 posted.

If that does not help there is a tsb no 3-16-1 aug/18
For the codes if they are stored in memory.
The deal with a new type valve cover.
A new fuel reg vacume hose .
intake gaskets.
And a PCM reflash.
Have your dealer run your vin no for tsb and recalls and PCM reflash on it.
MT-2500

when we bought the van last year the engine light came on about a month after-we took it back to where we bought it and he said he would have to bring it back to ford to reflash the computer and we didn't have a problem until today. Is there anyway to know if he fixed the bolts and the gasket? thank you for your help.

Hard to say. Have them check there repair records.
Did they put a reflash or campain sticker under the hood?
Does it have new or old style valve cover?
MT

MT-2500: at the risk of sounding like an idiot-what exactly is a campain sticker and how do I know if they actually did change the valve cover- because mine has the year 1999 on it!?

MT-2500: at the risk of sounding like an idiot-what exactly is a campain sticker and how do I know if they actually did change the valve cover- because mine has the year 1999 on it!?

There is a way to determine whether the Valve cover was replaced (The position of the hole in the baffle under the oil filler but I don't have the details handy).

The valve cover replacement is supposed to be a preventative measure to prevent oil from entering the intake. I personally did not buy into that philosophy and did not bother replacing the valve cover on mine.
If you have the new valve cover then chances are the entire TSB was performed however not having the new valve cover does not necessarily mean that the bolts have not been replaced.

The rubber around the bolts deteriorates due to oil contamination and this causes the lower plenum to manifold seals to leak. The only sure way is to remove the upper plenum and check the colour of the rubber surrounding the bolts. The new design is green and the old design is black (I think but someone please verify).

This really is not that difficult to check. There are about 15 bolts and then you should be able to lift the upper plenum up enough to shine a flashlight in to see.

I will bet that if you only had 50K when you bought it that it probably was not done before.

I am fairly sure that this will be your problem but I listed some other simple things to check first. (rather than blindly stating what your problem is). This Isolator bolt/port seal issue affects a lot of Windstars and the TSB is written such that when a customer brings their Windstar into Ford and they exhibit 171/174 and have no other drivability issues than they simply perform the TSB.

MT-2500: at the risk of sounding like an idiot-what exactly is a campain sticker and how do I know if they actually did change the valve cover- because mine has the year 1999 on it!?

When the dealer peforms a tsb or recall they put a notification sticker on it saying what tsb or recall or reflash they have done.
Look underhood and on drivers door for the sticker.
And like DRW1000 says there is no way to tell for sure on the valve cover and intake gaskets except to look at it.
MT

I only posted the tsb to help if all else failed.
Before you get into the TSB check out the things DRW1000 outlined in upper post.
Check fuel filter and fuel pressure and fuel reg. mass air flow sensor pcv valve and watch the fuel trims on a scanner or anything that can make it run lean.
Is the code stored in memory are they hard codes?
I think the tsb only refers to codes stored in memory.
MT

called the dealership where we bought it from and he said that they reflashed it and the light came on again so we had to bring it back and they told us that they changed the gasket. not sure if it was one or both? when we push on the accelerator you can hear a whooshing sound coming from the back of the engine.

You need to get it in and get it checked out.
Let us know how it goes
MT

thank you to everyone for helping and giving free advice unlike the ford dealerships but anyway bringing my windstar in monday mourning for a diagnostic check will let everyone now whats happening and how muchit will cost me thanks

Our check engine light went o over the weekend and we had it read- resulting codes 0174 and 0171(pending). the place we had it read turned the CE light off and it has not been back on again yet- it's been driven about 500 miles or so...should I be worried or wait until the light comes back on? There's no driveabilty issues now, nor were theree before the light went on...

Our check engine light went o over the weekend and we had it read- resulting codes 0174 and 0171(pending). the place we had it read turned the CE light off and it has not been back on again yet- it's been driven about 500 miles or so...should I be worried or wait until the light comes back on? There's no driveabilty issues now, nor were theree before the light went on...


If the lean condition returns, it will reset the code and give the CEL. Don't worry.

Our check engine light went o over the weekend and we had it read- resulting codes 0174 and 0171(pending). the place we had it read turned the CE light off and it has not been back on again yet- it's been driven about 500 miles or so...should I be worried or wait until the light comes back on? There's no driveabilty issues now, nor were theree before the light went on...
Tateresa
Welcome to your first post on AF.
That is a hard one to answer.
Not knowing the engine an year and model and mileage and tune up history.
Code 171 and 174 are lean codes. But many things can cause the codes.
If the system is actualy running lean it needs to be checked out.
I would suggest you get it checked out buy a good repair shop that is trained in diagnostic work.
Even if a code is not set or light on it still could be running lean.
And if it has never been tuned up like fuel filter and plugs and so on now would be a good time to do so.
MT

Our check engine light went o over the weekend and we had it read- resulting codes 0174 and 0171(pending). the place we had it read turned the CE light off and it has not been back on again yet- it's been driven about 500 miles or so...should I be worried or wait until the light comes back on? There's no driveabilty issues now, nor were theree before the light went on...
Tateresa
Welcome to your first post on AF.
That is a hard one to answer.
Not knowing the engine an year and model and mileage and tune up history.
Code 171 and 174 are lean codes. But many things can cause the codes.
If the system is actualy running lean it needs to be checked out.
I would suggest you get it checked out buy a good repair shop that is trained in diagnostic work.
Even if a code is not set or light on it still could be running lean.
And if it has never been tuned up like fuel filter and plugs and so on now would be a good time to do so.
MT

Our check engine light went o over the weekend and we had it read- resulting codes 0174 and 0171(pending). the place we had it read turned the CE light off and it has not been back on again yet- it's been driven about 500 miles or so...should I be worried or wait until the light comes back on? There's no driveabilty issues now, nor were theree before the light went on...
Tateresa
Welcome to your first post on AF.
That is a hard one to answer.
Not knowing the engine an year and model and mileage and tune up history.
Code 171 and 174 are lean codes. But many things can cause the codes.
If the system is actualy running lean it needs to be checked out.
I would suggest you get it checked out buy a good repair shop that is trained in diagnostic work.
Even if a code is not set or light on it still could be running lean.
And if it has never been tuned up like fuel filter and plugs and so on now would be a good time to do so.
MT

Our check engine light went o over the weekend and we had it read- resulting codes 0174 and 0171(pending). the place we had it read turned the CE light off and it has not been back on again yet- it's been driven about 500 miles or so...should I be worried or wait until the light comes back on? There's no driveabilty issues now, nor were theree before the light went on...
Tateresa
Welcome to your first post on AF.
That is a hard one to answer.
Not knowing the engine an year and model and mileage and tune up history.
Code 171 and 174 are lean codes. But many things can cause the codes.
If the system is actualy running lean it needs to be checked out.
I would suggest you get it checked out buy a good repair shop that is trained in diagnostic work.
Even if a code is not set or light on it still could be running lean.
And if it has never been tuned up like fuel filter and plugs and so on now would be a good time to do so.
MT

So I take it, this could have been jsut because we drove so far? We had driven over 400 miles straight before it went on...perhaps this was a factor??? I have grown not to trust the car- sometimes the interior lights come on for no reason... they will flash on, or even stay on for a long time- very strange!
Thanks for your help.:grinyes:

Is the TSB supposed to beat Ford's expense? Of course the light went back on and it's in the shop right now...it looks like it will need both the upper and lower Manifold gaskets replaced, etc, etc.... and will be pretty expensive. I am wondering- if this is a common problem and a TSB has been issued- why no recall?

Tsb's are only factory service bullitions that are put out to make a tech/mechanic aware of certain problems.
They really do not fix anything only point you to the problem.
And they are a you pay. A recall and the dealer will pay.
But there is a lot of known problems out there and it is almost always you pay unless under warranty.
The intakes gaskets give a lot of problems on gm and ford both.
But most are still you pay.
However Ford had a class action law suite against them on the 4.6 engine and are paying on some intake problems.
So hang onto your repair orders and maybe some day they will pick up the bill.
But do not hold your breath on it.
Good luck
MT

I figured as much. Why not just make a better car, right?! And why not make NEW parts to go in the cars that are better and will be compatable with the car?! I have already had the lower replaced once and am afraid to find out what both will cost me!

Recalls are normally only done for safety (read liability) issues. Design flaws such as this are not recalled but the benefit is that there is a known procedure to correct the problem. I have heard of some being able to talk the dealer into absorbing some of the cost or having it covered under the emissions warranty.

BTW the tsd is only for the upper portion of the intake and inludes the Isolator bolts, the port seals, the vaccuum regulator hose, one valve cover (depending on the year).

The interior light issue may be realted to the door switches. Do a search under interior lights and I think you will find that the problem might be in the rear hatch switches

Have the same problems. Repalced the plugs, wires, PCV, EGR and fuel filter. Took it to teh Ford Dealership and they said i needed to replace the intake o-rings and clean the EGR ports. Also replace the DPFE sensor. Don't think it's worth the $100 taking it to a dealer

Do these codes (lean) cause bad fuel milage? I live in Ohio, and warm the van up in the morn. for 10-15 mins, (in winter) and drive mostly in town, and I'm only getting a little over 10 mpg...I know I need to fix the code problems, and while I'm at give it a tune up, but just wandering what kind of milage you guys are getting...1999 Windstar 3.8l

Do these codes (lean) cause bad fuel milage? I live in Ohio, and warm the van up in the morn. for 10-15 mins, (in winter) and drive mostly in town, and I'm only getting a little over 10 mpg...I know I need to fix the code problems, and while I'm at give it a tune up, but just wandering what kind of milage you guys are getting...1999 Windstar 3.8l

Hello

We have a 95 and the worst millage that we can remember is 15 mpg. The best is around 23 mpg. If it's cold we try to warm it up just like you for 10 to 15 mins.

Regards

Dan

I'm just getting the whole thing done- Neither my husband or I have any idea how to fix anything on crs (I can change the bulbs myslef, though, rather than pay someone $20 to di it!) I am having everything the TSB advises done at a cost of $1075.00. As soon as financially possible, though, this car is going bye-bye and I will trade it in! I don't want to spend another $1,000.00 next time it happens! Will look into all the advice given for the lights, thanks! Where will I find the rear hatch swithces? I know, silly question, but, like I said, I am not car-literate!

Tateresa
Welcome to your first post on AF.
That is a hard one to answer.
Not knowing the engine an year and model and mileage and tune up history.
Code 171 and 174 are lean codes. But many things can cause the codes.
If the system is actualy running lean it needs to be checked out.
I would suggest you get it checked out buy a good repair shop that is trained in diagnostic work.
Even if a code is not set or light on it still could be running lean.
And if it has never been tuned up like fuel filter and plugs and so on now would be a good time to do so.
MT

I would suggest you get it checked out by a good repair shop first. Many things besides what the TSB calls for can cause the codes.
Tune up end is first thing. Fuel filter ,low fuel pressure ,pcv valve,maf sensor and other sensors and even sometime the PCM needs a reflash.
Good Luck MT

Good advice from MT-2500. Exhaust other possibilities.

What year is your Windstar. The TSB only covers 99 to 03 models with the 3.8L engine.

If it does turn out that you need the TSB performed I would shop around. $1075 seems high to me. Was this at a Ford dealer? I also do not feel the valve cover is necessary (but that is just an opinion). I would think that the port seals and bolts can be purchased for about $100 and I would suggest that 4-5 hours labour should be plenty.