Question about Ford Explorer Sport

1 Answer

I have a Can OBD2 scan tool my check engine light came on saw it PO171 system too lean bank #1 checked engine did not find anything loose or whatever so I cleared the light it came back on in two days same thing is this a oxgen sensor or where do i go from here. the engine is running a little rough

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 662 Answers

The codes I hear about most from Ford owners are P0171 or P0174; Fuel system lean, Bank 1 or 2. Now these codes indicate the engine is not getting enough fuel. This can be due to several factors, a bad Coolant Temperature Sensor (CTS), vacuum leaks or dirty injectors, among other things. One or more of the following symptoms accompanies these codes:

  • Lack of Power.
  • Spark Knock/Detonation.
  • Bucking and/or Jerking.
  • Hesitation or Surge on Acceleration.
However, I have come across on more than one occasion a fix that you might want to try before getting all stressed out and ********** in all for these possiblities.

I simply unbuckled the air cleaner, exposing the MAF. I then sprayed the two wires in the throat of the MAF with aerosol electronic cleaner. I used Chemtronics brand but I'm sure any brand of "fast evaporating" non-residue spray will do.

After the spray job, I waited one minute or so for the cleaner to evaporate and reconnected the air cleaner. After buttoning up the air cleaner, I erased the codes, it's been 700 miles and the codes have not returned! I suspect I had an ultra thin coating of dust/oil on the MAF wires.

As I saidm this is a common fault, and hopefully this will solve your concern.

Good luck and have a great day !!

Posted on Nov 10, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Check engine light is on and when tested shows codes PO174 and PO171

The P0171 means System too Lean (Bank 1) and P0174 means System too Lean (Bank 2).
FGTech Galletto 2-Master

Nov 08, 2012 | 2004 Suzuki Verona

1 Answer

Check engine light obd code po171,po300,po302,po303 1997 camry 2.2 ltr.

PO171 OBD2 Code basically this means that an oxygen sensor in bank 1 has detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1. The P0171 is one of the more common trouble codes.

his code is triggered by the first downstream (front) O2 sensor. The sensor provides a reading of the air:fuel ratio leaving the engine's cylinders, and the vehicles powertrain/engine control module (PCM/ECM) uses that reading and adjusts to keep the engine running at that optimum ratio of 14.7:1. If something is not right and the PCM cannot maintain the 14.7:1 ratio, but rather there is too much air, it triggers this code.

Nov 06, 2012 | 1997 Toyota Camry

1 Answer

2005 lincoln aviator codes po171 po174 p2195 p2197

This DTC is a very common issue on the V6 and refer at the little rubber elbow on the PVC wears through.

P0171 - System Too Lean (Bank 1)

- System Too Lean (Bank 2).

Those lean codes are for a lean fuel condition. The first thing I would check is for a vacuum leak. Especially look around the PCV system. Look for soft or collapsed hoses in the PCV system, (especially the rubber elbows) these are very common issue for failure and cause of lean codes. Also check around the intake manifold for leaks or any other hoses that may have come off.

Next I would check fuel pressure and the fuel filter for blockage. If the filter is old you might as well replace it. If and when you find an issue you will have to have a scan tool to reset the check engine light before you go back through emissions.

Check that stuff and let us know what you find.

Sep 30, 2011 | 2005 Lincoln Aviator

1 Answer

Please tell me what this means,,, po171 band 1 system too lean and po174 band 2 system too lean, thank you, jill

PO 171--is an O2 Sensor Code for a Lean Condition
on Bank 1 (right side exhaust)

PO 174 -- is an O2 Sensor Codes for a Lean Condition
on Bank 2 (left side exhaust)

You gave us no vehicle
You gave us no drivability issues or
vehicle history,nothing

If the O2's have 100,000 miles on them,change the (2)
closest to the engine. They are most likely worn out
& the switching times are too slow to control injector
pulse width & thus set a MIL Lamp (OBD2 Fault ) on
your dash

You can learn a lot on the internet if you put OBD2 in your
Search Engine (Internet Explorer,etc)

Jul 15, 2011 | Lincoln Town Car Cars & Trucks

1 Answer

02 stratus, 3.0, Code PO171, Lean on # 1 bank? Could this be something "other" than injectors?

It would help if you could get the car scanned with vag-com, it will show the full fault code.

P0171/ Fuel Trim; Bank 1: System Too Lean
Possible Causes

* Mass Air Flow Sensor defective

Possible Solutions

* Check Mass Air Flow Sensor
* Check Fuel Pressure Regulation
* Check Fuel Pump
* Check Injectors
* Check Intake System for Leaks
* Check Exhaust System for Leaks
* Check Secondary Air System for Leaks
* Check Vacuum Pipes for Leaks

Mar 16, 2011 | 2002 Dodge Stratus

1 Answer

1999 chevrolet 1500 with a 5.3 engine engine light on had check had a code in it po171 and po174 sey burning to lean on bank 1 and bank 2 what should i check for did pass inspection

Running lean on both banks? Check intake tubing/hoses for loose clamps and cracks/tears aft of the mass airflow sensor. Could also be a fairly large vacuum leak.

Mar 06, 2011 | 1999 Chevrolet Silverado 1500

1 Answer

Check engine light is on codes are po171 system too lean (bank 1) po174 system too lean (bank 2) so what can i do

Look for vacuum leaks,that are causing the O2 Sensors to go lean, and set codes on both banks

Nov 11, 2010 | 1997 Ford Expedition

2 Answers

A po171 code came on my scanner i need to know

system too lean in bank 1. clean your mass airflow sensor, replace fuel filter. iff all else fails check you fuel pump.

Nov 06, 2009 | 1998 Ford Contour

1 Answer

Don't know what system lean bank means.

hi it means you have a lean fuel/air ratio on the cylinders on that side of your engine look for air leaks [hoses gaskets loose manifold bolts etc yates210456

Oct 19, 2008 | 1996 Plymouth Neon

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

55 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts


Level 3 Expert

79186 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers


Level 3 Expert

5677 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides