Codes 171 & 174 too lean

While I was surprised to have the intake leakage problem it has been a very reliable and quiet vehicle. It has had several recalls though. The worst was a possible fire problem with the rear blower. The item was replaced, but overheated anyway. I repaired it myself and it has been great since. I am (at this point) completely satisfied with the vehicle though. I wait until you stop gasping for air.

Why... modern vehicles are EXTREMELY complex machines. The consumer is expecting better cars and want to pay as little as possible for what they want. This simply isn't possible. My wife's van (yes, it's hers... I drive a F-350 7.2l diesel) has been an extremely good primary, trucking the family and stuff around, vehicle. It has 67k on it and still runs and looks great. One thing I have been sure to do is keep up with ALL the maintenance. Fluid, coolant, oil; you name it, it gets changed. The transmission is still great. Smooth shifts, quiet, no lags or slipping.

I am statisfied.

Pcitizen,

Excellent work! This will help even experienced wrench-turners.

Thank you!!!

I just went through this 171/174 problem. After the check engine light came on 3 weeks ago, I was getting only 171 and I cleared the code. It came back on last week and now was getting 171 and 174. Estimate from Ford dealer was $740. While checking this forum for DYI info I found that Ford was providing some assistance after warranty to correct this TSB 03-16-1 problem. I checked with the dealer and found the following: After-warranty adjustment was available up to 70,000 miles. My Windstar has 53,000 and is out of warranty. Ford covered 70% of the cost. The dealer applied the money I already paid for the diagnostics and I was out the door with another $140. I would have spent that much on parts to do it myself.

Well I took the van to the stealer yesterday. I told him I had the P0171/0174 codes set. I showed him the TSB 03-16-01 and asked that if they came to the same diagonosis would it be covered under my extended powertrain warranty (that I had to buy because of a transmission failure at 40K miles). He confirmed it would and said that if that was the fix I would only own the $100 deductable on my warranty... Well I got a call last night that confirmed the TSB would be the fix and that I could pick up the van this morning... My total bill $100. At least now I feel like I'm getting something out of that transmission failure.

Oh and by the way, ever since they rebuilt the transmission, the van pulls to the left going down the highway. It's been "alligned" twice and still there is an anoying pull. I contend they bent something when replacing the transmission, but at this point it's impossible to argue. Lesson learn... don't ever except completion of major repairs until everything is just the way it aught to be.

Pcitizen, great work on the pictures and steps for the fix. One request though, your details and link are kind of buried in this thread way down on the 4th page. Could you post a new thread with your link and a descriptive title so it will stand out better for the many Windstar owners that come here looking for help on this issue? Thanks again for sharing this info.

Great idea lewisnc100. Part of the fun is reading all this to get to the good stuff... knowledge.

I have set up a cheesy web site that explains how to do the TSB repair discussed in this forum. Take it as it is. Cheesy-factor is pegged, but I think it will be helpful for some of you do-it-yourselfers.

Here's the URL.

http://leckemby.net/windstar/windstar01.html

I Have Been Following This Thread And Have The Same
Problem And Going To Follow Your Instructions.i Have
One Question Does The Pcm Have To Be Re-programed
After Fix.

Thanks Gitzy

I have read comments here that say no. I did not have mine reprogrammed. I would suspect the answer is, in fact, no. I cannot see how any of the new parts for this fix could alter the system to require programming adjustments. Ford has likely added this as a "to do" to merely update the systems with the latest changes.

Anyone... anyone... Bueller... Ferris Bueller.

..That you, Ben?

My 2001 winny just popped the 171/174 too lean codes a couple of days ago. It has about70K and this is the first problem with the vehicle. My question is we are getting ready to go on about a 1000 mile trip and I do not have time to take it in or fix it myself - should I risk driving that distance with the codes or plan on taking another vehicle (ie rental)? There is no perceptable decline in performance since the CEL came on.

I'd make the trip. It took me a while to get around to mine when the CEL first came on ... in fact the CEL "came and went" a couple of times before performance problems were noticeable.

Of course, your experience may be different....its a small gamble, but at least you're keeping your money in your pocket.

You might also check for the easiest cause of the P0171/P0174 error codes before your trip. I got those codes and was convinced that I would need to perform the entire TSB repair. But when I looked at the engine the fuel pressure regulator vacuum line had loosened up and fallen off. This is the first check in the TSB and I was lucky, replaced it and the valve cover and haven't seen the errors back (although I'm sure I'll be doing the TSB steps some day). Here's a picture of the vacuum line:

http://groups.msn.com/FordWindstar/shoebox.msnw?action=ShowPhoto&PhotoID=24

<snip>...the fuel pressure regulator vacuum line had loosened up and fallen off. This is the first check in the TSB and I was lucky, replaced it and the valve cover and haven't seen the errors back (although I'm sure I'll be doing the TSB steps some day). Here's a picture of the vacuum line:
</snip>


Thanks for the thoughts... although I may have spoke too soon - my wife just called and said the car was sputtering and running rough. We are in the throws a very cold spell and I think I read somewhere that cold weather will exacerbate the problem. I will check the vacuum lines and let you know. Also will the CEL clear automatically or do I need to reset it. If so how? Thanks!

If you fix the problem the Powertrain Control Module will clear the CEL after some miles of driving.

I just found this forum today, and all of the TSB links I've tried are long dead... Does anyone know how I can get a copy? Thanks.

Cowboy,
The codes will clear after a few drive cycles after correcting the problem.

88Duke,
The TSB for the lean codes is burried less than a month into this forum. I am sure they are still active. Search for 171/174, Isolator bolts, intake leak.....

Excellent thread post and thanks for the webpage instructions pcitizen. I have a '99 with 67K miles that just started pinging the 171 and 174 codes. It had to drop below 50 degrees here in Phoenix to start seeing them.

I should have known that something like this would creep up. We had a '91 Tracer (escort in mercury clothing) which had problems with oil blow back into the intake filter box through the PVC piping(1.9l engine).

I will say, however, that the 3.8l in my '89 cougar had zero engine issues and is now over 150K miles in the hands of a different owner. My only gripe with it was that a $2 throttle kick-down bushing deteriorated and jammed the car at full throttle in rush hour traffic one day. There were over 100 NTSB reports about cougars and t-birds running away and crashing, but no warning from Ford about it.

As far as warranty coverage, isn't the emissions system covered for 10 years? The CEL codes indicate that the engine is running too lean and may be exceeding HC levels. Any car exbiting a CEL during emissions testing here in the southwest automatically fail the test. If this is a systemic intake malfunction which causes the vehicle to fail emissions, then it should be covered under the emissions warranty. This may explain why they are willing to pay for the labor in some circumstances.

Well this is what I have determined based on this and the Cartrackers forum. I just bought a 99 Windstar LX on Ebay and the check engine light is on. I have not had the codes read but from all appearances on this site I have to assume it is likely 171/174.

1. First one must determine whether one wants to do anything about this at all. I live in a state where they don't do emissions testing, the van seems to run fine, and if there is some impairment of fuel economy, how much gas must one burn to pay for what sounds to me like dismantling the whole engine. On this site and Cartrackers I have seen estimates of 1200-1400 for this repair. Or, several hundred in parts, plus my time (assuming I had the right tools)(and knew what I was doing)(which I don't).

If you have 171/174 and the van eventually dies (If it does), will it even be Worth 1200-1400 at that point. (My van has 109k, and I paid 2700 for it.)

2. OK, assume you simply Must deal with it. My reading suggests the following triage:

a) do routine maintenance -- change oil, oil filter, air filter, fuel filter, PCV valve and sparkplugs. Reset. If it comes on again,

b) replace the DPFE sensor. Reset. If it comes on Again,

c) replace the 2 oxygen sensors (front and rear?). Reset. If it Still comes on,

d) proceed with TSB 03-16-1 and have checkbook and a stiff drink at hand.


Or, am I missing something critical??

Many thanks.

Jimsaco.... 1200-1400! I am not sure where you've read that fixing the 171/174 code problem costs that much. It was closer to $100 if I recall. I think this is a relatively cheap repair and to me, worth it.

Please take a gander at http://leckemby.net/windstar/windstar01.html

PCitizen

I would skip the oxygen sensor replacement....as the TSB is FAR more likely the issue. The oxygen sensors rarely fail.

You will have 4 oxygen sensors.
1 before each of the 2 catalytic converters.....which are the ones that are used for engine control....as in air/fuel mixture for banks 1 and 2.

You also have 1 after each catalytic converter.....they are used to monitor the catalytic converters to make sure that they are doing their job. They are not used for engine control.

There are a lot of oxygen sensor specific codes to tell you if there is an oxygen sensor failure.

I'm writing to hopefully provide solace for those who are perplexed by these two bewildering codes. I recently had an issue with these two codes occurring together. From the outset, I paid for a diagnosis at the service dept of my local Ford dealership. They failed to make a diagnosis. I made it clear to them that I had no intention of throwing thousands of dollars at every symptom they could come up with (...and belive me there are many variables); but apparently this had been their plan. It's inconceivable that the mechanics would have had no experience in dealing with other distressed Explorer owners--enough to know how to resolve the issue without expensive "guesses". Once I paid for a diagnosis I was determined to hold their feet to the fire--showing up at the service dept everytime the light came back on. Eventually, I gave up and begin the arduous process of elimination. I had spent approximately $300-350 replacing the (mas airflow sensor, Throttle position sensor, and the oxygen sensor). After replacing all these, the light immediately came back on. Forutnately, I took it to a trustworthy mechanic who did a thorough investigation (before my very eyes), before rendering an opinion. He said that the problem was most likely the (intake-manifold gasket). I paid him 225.00 for the diagnosis and to replace the gasket and I've been worry-free ever since. The point I am trying to make is for anyone distressed by this should first consider this before spending hundreds of dollars needlessly in replacing all the sensors. Undoubtedly, it's a money making scheme--dreamed up by the engineers at Ford.

Thanks for the response... Nothing to do with oxygen sensors. Someone on the forum mentioned the technical service bulletin TSB 03-16-1. Look for it. It explains the procedure to solve the problem. This was a design flaw, for which Ford, I guess, decided that it is up to the customer to pay to have it fixed. There is a kit available with all the required parts (valve cover, a piece of hose, and some bolts with a rubber seal and intake manifold gaskets. The parts cost 300$ and the garage wanted 800$ to do the job... saying it is very complicated to do....

So, being anything but a mechanics... I took my intelligence out of me and did the job by myself. First time I dismantled parts in a car that I would need to get to work the next morning. Well, I started at 6pm and finished at midnight, and the TSB, being clear, it was easy to do. I suppose that somebody with a bit more experience would have done it in half that time.

39186

39187

39188

39189

39190

Can anyone advise what to do now that I've snapped two of the bolts off? I am not sure how to completely remove the lower plenum to gain easy access but the bolts are located in the front, adjacent to each other. I know I'm not the first to have done this. They have the green sleeve and are new. Can I leave them in and add a gasket sealer just under the top of the bolt? Anyone know what other people did to fix their snapped off bolts? it is pallius@gmail.com if anyone can help.

Thank you!!

...... I know I'm not the first to have done this. ...... Can I leave them in and add a gasket sealer ......? Anyone know what other people did to fix their snapped off bolts? .....i.

Yes, you can be sure that others have had the problem of snapping these bolts. Part of the problem is the "units of torque measure" that was choosen ... few folks don't notice that it is 89 inch-pounds (not " foot-pounds"). 89 inch-pounds ... that's not much torque!... (about 8 foot-pounds) ... many of us can twist a screwdriver with more torque than that!

And some folks think that some extra added torque will help seal a leaking bolt. NOT SO!! Once the center-bolt-head draws down tight against the inner steel sleeve ... that's all the sealing you are gonna git!!!

And many folks don't obtain and use a small torque wrench. 1/4" drive beam torque wrenches are available ... just a bit hard to find.

There is no short cut that will work ... the old bolts must be removed and new ones added. You may find yourself having to remove the lower metal intake manifold to avoid getting drill shavings down into the engine. This also is not that difficult ... but it must also be done correctly or you will have even greater issues.

Good luck!

I recommend cleaning the mating surfaces with acetone. Then covering the intake ports with blue painters tape.

Use a center punch dimple the center of each bolt. It is important that your dimple is in the center because once you start drilling you don't want to drill into the female threads.

Then drill it with a 1/6 inch carbide tipped bit. Drill about 1/2 to 5/8" in to the screw. Then drill it with a 3/32 or 1/8 inch carbide bit.

Use EasyOuts. These are reverse, tapered, screw-like items. As you screw them in (counter clockwise) they should bight into the broken off screw and remove it easily. They work great. Most auto parts stores sell them but I would buy a high quality set - Craftsman or similar.

I do not recommend using gasket sealer to remedy the problem. In fact, the mating surfaces don't require gasket sealer at all thanks to the presence of space-age, heat resistant, highly fantastic, super elastic, rubber seals.

Be patient and you;ll have good success.

PCitizen.

I am not saying the problem couldn't be the intake manifold gaskets, but it seems this thread needs refreshed.

The 171 and 174 codes are very likely related to the bolts used to hold the intake manifold on. At least that was the cause in 2000 Windstars and similar year automobiles with 3.8 engines.

Ford, and others, sell kits to remedy the problem; e.g., oil destroyed the shoulder bolt seals. Ford made new bolts, and found valve cover needed replaced too.

Check out http://leckemby.net/windstar/windstar01.html for a tutorial on the fix.

PCitizen.

Just today I performed the "Pcitizen Special". Walkthrough was amazing and handy... especially since the most I've ever done in the past is change my own oil.

So, at the very end of the process I was putting on all of the vacuum tubing/hose and when I was re-attaching one of the tubes to the DPFE Sensor (the black polymer one) it tore on me... I started up the Windstar anyways, which thankfully it did run, but had a very rough idle I'm assuming is from the torn tube.

I took it off the van and headed to Auto Zone. They couldn't find anything to 100% match so they sold me a 1/4 in. fuel injection hose. It looked good at first but the tubing is just too stiff to attach.

I've tried many different searches but just can't find the right hose for the job... anyone know what I should do next?

EDIT: Advanced Auto Parts had the hose I needed. I repaced the hose, but the rough idle still exists! I didn't have this rough idle before I did the valve cover replacement / isolator bolt job. Any thoughts to this? Maybe another vacuum leak?


Joe

Many hoses these days are molded types. I recommend buying an exact replacement.

I figured out the rough idle... one of the last things I did was to re-plug in the spark plugs. After close examination I had attempted to plug the connector into an extended bolt that was close to the spark plug.

FYI, bolts don't give the same results as spark plugs. :P

After the rough idle was settled, the engine runs MUCH smoother. Now on to the next thing - replacing the idler pulley and belt tensioner to hope it solves the whining sound I'm hearing.