P1151, P1131, P0174, or P0171 on Ford Duratec

Rick — Mon, 22 Dec 2008 04:52:00 +0000

All four of these codes indicate a problem with a lean condition. This engine is known for vacuum leaks, so before you start throwing oxygen sensors at the problem, it pays to perform some diagnostics.

Start by cleaning the MAF sensor. Spray the sensor with CRC MAF sensor cleaner (even though Ford tells you to replace it because it can’t be cleaned). Next, check the plastic vacuum lines, especially where they meet with rubber boots. If they are cracked or the rubber is swollen, replace the line. Then check the rubber elbow that holds the PCV valve. That elbow is a know failure point. In fact, the entire PCV tubing is a trouble spot on these engines. (thanks Ford).

After you’ve checked for vacuum leaks, check the operation of the oxygen sensors. The easiest way to do that is to disconnect the sensor from the harness. Connect one lead of your digital voltmeter to the black wire on the sensor and the other lead to battery negative. Then start the engine and add fuel (either propane, starting fluid, or carb cleaner) into the throttle body to force the mixture to rich. You should see a corresponding increase in voltage as you add fuel (from 0 volts to slightly less than 1 volt). Start and stop the fuel enrichment and watch the meter to see if the volts drop as you stop adding fuel. If you see no change, the sensor is dead. Replace it.

You can also use the fuel enrichment procedure to locate intake gasket leaks.

P1131 Lack of Upstream Heated Oxygen Sensor Switch – Sensor Indicates Lean – Bank No. 1

P1151P1151 Lack of Upstream Heated Oxygen Sensor Switch – Sensor Indicates Lean – Bank No. 2

P0174 system lean bank 2
P0171 system lean bank 1

For more information on this repair or any others for your vehicle, buy an online subscription to either Alldatadiy.com or eautorepair.net. Click on this link to compare the two services: Compare Alldata and Eautorepair.

If you just need information for a single repair and want to save money,eautorepair offers a lower price 1-week subscription for only $11.99. Or, if you’ll be working on this vehicle in the future, you can buy a 1-year subscription (Alldatadiy.com for $26.99, or eautorepair.net $29.99)

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Hover your mouse over the REPAIR ARTICLES tab at the top of the page. The click on DIAGNOSTICS to search by SYMPTOM, TROUBLE CODE, or read TECH TIPS on how to diagnose a problem

Click on MAKE an MODEL to see all the articles I’ve written for your vehicle
Click on REPAIR TOPICS to read individual articles written for specific automotive systems

If you’ve had your car scanned and know the trouble code go to TROUBLE CODES

Here are some quick links to speed up your research

Click on the link below for speedy navigation:

ABS issues, how to bleed ABS brakes

Airbag issues or SRS light on

Alternator issues or how to test

Belt diagram or serpentine belt issues

Blower motor

Blower motor resistor

Brakes, brake issues, what kind of brake parts to buy, ABS issues

Car Alarms or Antitheft systems

Cooling system, Water pump, What type of coolant to use

Engine flush

Firing order, cylinder layout, finding #1 cylinder

MAF or MAP sensor

Oxygen sensors, How they work, How to change, How to test

PassLock or Passkey

Thermostat issues

Transmission flush

Serpentine belt diagrams

Window issues, power window motor, replace window regulator, glass adhesive

Ford door switches—a known problem

Rick — Wed, 02 Apr 2008 03:21:00 +0000

Remember the pin/plunger switches that car makers used to install in the door jamb? Well, you won’t find them in Fords—some brilliant engineer had a “better idea.” They decided to place the switches inside the door right under the latch mechanism. When the door latches, a lever deactivates the switch and the body control module turns off the interior lights. Good so far….. The problem is that the switches gum up with grease from the latch mechanism or corrosion. That’s when interior lights stay on.

Some shops have reported success by saturating the latch mechanism with a rust penetrant and opening and closing the door about 20 or 30 times. That works the penetrant into the mechanism and some of it finds its way to the lever and switch. You really don’t have much to lose by trying this method because the only alternative is to remove the door trim panel and replace the switch.

I’ve tried this on a few Ford vehicles and had success. However, it’s not a long term fix. You will have to do it about twice a year.

Find a replacement ford door lock switch here