1999-2003 Windstar has rough idle - has OBD codes P0171 and P0174 and feels like it's ready to stall?

Answer 1

Answer

I have just recently started having misfire issues with my 2000 with a 3.8 ltr. I had the dealer that I use run a full computer scan on it. It came back with rear o2 sensor, map sensor, cam position sensor and FUEL INJECTOR 1. Guess what, no exhaust leak.. o2 sensor ok.. mechanic said replace injector 1 and all other codes will go away. I have asked a couple other mechanics and they all say the same thing, bad fuel injectors will reek all kinds of havoc and throw odd codes. If your vehicle is suffering from a rich or lean mixture, make sure you have it scanned at a reputable Ford dealer for fuel injector issues, it might just save you a lot of money and they are not hard to change yourself. Oh, by the way, don't buy the injectors from the dealer unless you are going to have them change them. Most dealers charge between 65 and 75 for each injector. I found them at advance and o'rielly's as well as on e-bay for a lot less. Problem solved on my van. Good luck!!

AnswerI just recently became aware of this common problem with 1999-2003 Windstars.

The first, and most persistent indicator that this MIGHTbe a problem is getting P0171 and P0174 scan codes - they indicate a lean condition Bank 1 and Bank 2.

Another symptom is a rough idle - and it may be an intermittent rough idle.

There are other diagnostics cited at both of the linked resources to confirm if your Windstar may be afflicted with the problem.

For reference, there is a TSB (technical service bulletin) officially recognizing the problem and a proposed remedy: TSB# 03-16-1

There's an exhaustive photo guide and discussion regarding this repair via the "Related Links" below.

Be Warned: if you do visit AutomotiveForum.com, as the gentlemen suggests, it's addictive to want to read everythingavailable on the Windstar!

Check PVC grommet in the valve cover. Should be tight around the PVC. Check the Fuel Pressure Regulator Vacuum Line. It has a tendency to swell and leak at the Regulator end.

AnswerI means you need to have your intake manifold gaskets replaced and perhaps the valve cover too. I had this done on my Windstar , here is a link that explains it all.

http://leckemby.net/windstar/windstar01.html (linked below)

I did this myself for less than $80.00 very simple.

Fuel problem:

• Fuel filter needs replacing
• Fuel pump is failing - check pressure

Vacuum leak?

Bad gas or Ethanol

This is usually caused by vacuum leaks that the average person cannot fix. It can be repaired by a reputable mechanic for around $850.00 but once it is fixed, it's fixed and you won't have to keep going back again and again for the same codes.

AnswerIt is very possible your Mass Air Flow sensor is sending bad signals to your pcm. They can cause screwy problems sometimes. This should also be throwing a fault code. Is your check engine light comming on? If so have the fault codes ran. If not the only other way I can think of is to hook up the computer to a real time scanner and compare the values of the sensors with the values they should be. You will need access to a factory manual for this though.

it soundslike a misfire or multiple misfire. check the plugs, wires, ignition coil, and the timeing. those are the usual causes, bad head, head gasket, or crank angle position senser have the same simptoms so further probing might save trouble later

I also have a 2000 Ford Windstar. I replaced or checked the following.

1. Replace Idle air control valve. $80.

2. Fule filter $10.

3. Make sure vacume hoses behind air filter box is connected.\

4. Replace PCV valve. $6

5. Make sure the spark plugs are not over 4 years old.

bad o2 sensor or active fault code it needs to be scaned auto zone does it free

Trouble code P0171 means: Fuel System Too Lean (Cylinder Bank 1)

Trouble code P0174 means: Fuel System Too Lean (Cylinder Bank 2)

More info...These 2 codes are common indicators of a well-known failure on the 1999-2003 Windstars. Be sure to review the additional information in the "Related Questions" below...

I would like the whole list of error code.I have other codes,but my manual don't have this other codes

Remove the negative cable on your battery for about 5 min. It should clear any codes stored in the ECU.

I own 1999 Ford Windstar XL 3.8l engine, and I have same codes P171-P174 it is mean for lean codes of upper bank. Diagnosing the codes gave so much about it. I decided to take it to the dealer and they told me sam code for various problems. Bill to repair is about $1200.00.I did repair by my self and find that lower and upper intake plenum gaskets went bad.After that no codes at all. Repair was done 3 years ago.That is the cure of the problem and cost me 8 hours of my labor and $275.00 in parts.I have around 95000 miles on it .