2005 Mercury Mountaineer Logo
A
Anonymous Posted on Aug 13, 2014

Bank one and bank two

System lean and oxygen sensor possible, bank one and bank two engine light came on without any car problems

1 Answer

mmpp20

Level 2:

An expert who has achieved level 2 by getting 100 points

MVP:

An expert that got 5 achievements.

Governor:

An expert whose answer got voted for 20 times.

Hot-Shot:

An expert who has answered 20 questions.

  • Expert 29 Answers
  • Posted on Aug 13, 2014
mmpp20
Expert
Level 2:

An expert who has achieved level 2 by getting 100 points

MVP:

An expert that got 5 achievements.

Governor:

An expert whose answer got voted for 20 times.

Hot-Shot:

An expert who has answered 20 questions.

Joined: Dec 22, 2008
Answers
29
Questions
0
Helped
40806
Points
142

Usually when you get lean on both banks it points towards a vacuum leak or weak fuel pump. It is unlikely that both front oxygen sensors went bad at the same time...not impossible...but unlikely. If the manifold gaskets are worn it could produce a small vacuum leak when cold and you don't notice it because the system is in open loop and compensating with fuel. As the manifold heats up and expands the leak disappears and you never notice the issue but the module still sees the unmetered air.

5 Related Answers

Anonymous

  • 104 Answers
  • Posted on Jul 16, 2009

SOURCE: Check Engine Light Problem

Codes that tell you your engine is running lean can be caused by a number of things. First thing to do (and cheapest) is to get some fuel injector cleaner and run it for awhile. Dirty injectors can cause these codes. I recommend lucas brand myself but there are several different cleaners to choose from. The second thing is checking your vacuum lines. If there is a leak it can cause the engine to **** in too much air and cause the codes. Anything beyond that gets into alot of mechanical work and should be done by a certified technician

Ad

Anonymous

  • 68 Answers
  • Posted on Mar 08, 2010

SOURCE: 97 Mercury cougar xr7 v6. po443, po430, po171, po174,

Sounds like you have low fuel supply or a leak in intake system causing lean codes, check fuek pressure and volume first. Cat converter effeciancy could be caused by the lean codes, purge system sounds like solenoid failure, check for high resistance accross purge vent solenoid.

Mike

  • 4383 Answers
  • Posted on Jul 26, 2010

SOURCE: My check engine light is on, I got 3 error

Look for intake leaks, espeically near #1 cylinder. sounds like major intake leak.

kapishtech

raj somaiya

  • 2272 Answers
  • Posted on Oct 01, 2010

SOURCE: recently had my smog done check engine light w 3

P0171 indicates a lean condition. The most common cause of this is a defective mass air flow sensor. Also check if any vacuum leaks.
P0174 OBD-II Trouble Code Technical Description

System Too Lean (Bank 2)
What does that mean?

Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust.

Note: This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.

-----------

P0430 means you're going to buy a cat. (And you'll have to fix the coolant leak.)Catalyst System Low Efficiency (Bank 2) .Also check O2 sensors .

Thanks.

Anonymous

  • 1 Answer
  • Posted on Oct 11, 2010

SOURCE: I have a 97 Mercury

1997 sable code is PO155

Ad

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

0helpful
1answer

What does code p1131 mean on a 2001 ford taurus

bank 1 sensor 1 lean code. Check vacuum lines first. Could be egr leak also. Most vacuum lines run on the back side of the engine on these. Most common fail is the PCV 90 degree elbow. On the passenger side.
1helpful
1answer

Codes P2270& P2272 after oil change check engine light on drove under 100 miles both O2 sensors bad .Could shop have caused this somehow??? Maybe banging them or something ?

make sure they are plugged in tight Definition of Diagnostic Trouble Code P2270 Category: Powertrain Definition: O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 2Note: This definition of P2270 is applied to all manufacturers

P2270 - O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 2 Comments ' Add Yours
Possible causes
- Faulty Rear Heated Oxygen Sensor Bank 1
- Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Exhaust gas leaks Help with this
When is the code detected?
The Powertrain Control Module (PCM) detected the HO2S12 sensor has reported a lean condition for an extended period during an intrusive test
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- High Fuel Consumption
- Excessive Smoke from Exhaust
P2270 Description
The Powertrain Control Module (PCM) supplies a voltage of about 450 mV between the HO2S high and low signal circuits. The oxygen sensor varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean.
The PCM monitors and stores the heated oxygen sensor (HO2S) voltage information. The PCMevaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period and determines if majority of the samples are out of the operating range.

Definition of Diagnostic Trouble Code P2272 Category: Powertrain Definition: O2 Sensor Signal Biased/Stuck Lean Bank 2 Sensor 2Note: This definition of P2272 is applied to all manufacturers

P2272 - O2 Sensor Signal Biased/Stuck Lean Bank 2 Sensor 2
' Add Comment
Possible causes
- Faulty Rear Heated Oxygen Sensor Bank 2
- Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Exhaust gas leaks
What does this mean?
When is the code detected?
The Powertrain Control Module (PCM) detected the HO2S22 sensor has reported a lean condition for an extended period during an intrusive test
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- High Fuel Consumption
- Excessive Smoke from Exhaust
P2272 Description
The Powertrain Control Module (PCM) supplies a voltage of about 450 mV between the HO2S high and low signal circuits. The oxygen sensor varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean.
The PCM monitors and stores the heated oxygen sensor (HO2S) voltage information. The PCMevaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period and determines if majority of the samples are out of the operating range.
P2272 Information for specific makes
P2272 BMW
P2272 DODGE
P2272 FORD
0helpful
1answer

Ford focus 1388/16v cod p1131

Possible causes
- Faulty Oxygen Sensor
- Vacuum leak affecting bank 1 only
- Fuel injector problem bank 1
- Check for cylinder misfire on bank 1
- Engine mechanical conditionTech notesThough the Oxygen (O2) sensor, the Engine Control Module (ECM) has detected a lean system, which means that there is either not enough fuel or and excessive amount of air in the system. Start by checking for vacuum leaks.
4helpful
1answer

Code po171 system too leen bank 1

DTC P0171 - System Too Lean (Bank 1)
Basically this means that an oxygen sensor in bank 1 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.

Note: This DTC (Diagnostic Trouble Code) is very similar to P0174, and in fact your vehicle may show both codes at the same time.

I would suggest that you take a look at the front oxygen sensor. Typically speaking the oxygen sensor causes this code to appear. Here is the possible cause list from the manual for your car.

Trouble Code: P0171 - Fuel System Lean (Bank 1)

Possible Causes:
Air leaks in intake manifold, exhaust pipes or exhaust manifold
Base engine mechanical problem causing a lean A/F condition
Fuel control Sensor is out of calibration (e.g., ECT, IAT or MAP)
Fuel delivery component fault (clogged filter, low fuel pressure)
O2 element is contaminated, deteriorated or it has failed
Vacuum hose is disconnected, broken, leaking or loose

Hope this helps (remember to rating this answer ans leave us a testimonial comment). Thank you for using FixYa.
1helpful
1answer

2003 Chrysler Town & Country po171 code

DTC P0171 - System Too Lean (Bank 1)
Basically this means that an oxygen sensor in bank 1 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.

Note: This DTC (Diagnostic Trouble Code) is very similar to P0174, and in fact your vehicle may show both codes at the same time.

I would suggest that you take a look at the front oxygen sensor. Typically speaking the oxygen sensor causes this code to appear. Here is the possible cause list from the manual for your car.

Trouble Code: P0171 (2.5L V6 Auto) - Fuel System Lean (Bank 1)

Possible Causes:
Air leaks in intake manifold, exhaust pipes or exhaust manifold
Base engine mechanical problem causing a lean A/F condition
Fuel control Sensor is out of calibration (e.g., ECT, IAT or MAP)
Fuel delivery component fault (clogged filter, low fuel pressure)
O2 element is contaminated, deteriorated or it has failed
Vacuum hose is disconnected, broken, leaking or loose

Hope this helps (remember to rating this answer ans leave us a testimonial comment). Thank you for using FixYa.
0helpful
2answers

What does error code p0172 and p0174?

P0172 - Fuel Injection System Too Rich Bank 1 Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Excessive Fuel Consumption
Possible causes - Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connec
Possible solution Dirty air filter of faulty air flow sensor are common causes of the problem.



P0174 - Fuel Injection System Too Lean Bank 2 Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Excessive Fuel Consumption
Possible causes - Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connection
Possible solution Dirty air filter of faulty air flow sensor are common causes of the problem. Bottom line possible defective Mass airflow sensor and or O2 sensor in cylinder bank number two.

1helpful
1answer

I have a 04 expedition the engine light came on the code read po171 and po174 it die out when I'm at a red light but cranks back up missing bad when it warms up

P0171 - Fuel Injection System Too Lean Bank 1
Possible Causes:
- Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connection

P0174 - Fuel Injection System Too Lean Bank 2
Possible Causes:
- Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connection
1helpful
1answer

Engine light on 3 codes in system

The lean running codes are related to the p-1000 code...

Running lean on bank 1 and bank 2 means your oxygen sensors sense too much oxygen in your exhaust flow. This means either your engine is getting unmetered air (air that the engine does not know is coming in, therefore does not send fuel to compensate for...) (air that your mass air flow sensor does not see). You could have either a bad mass air flow (MAF) sensor (in the intake piping after the filter; this sensor tells your engine how much air it's taking in, so it can send the right amount of fuel through the injectors to properly burn with the air available with as little emissions as possible), or you could also have a cracked/broken intake piping after this sensor which lets air in the intake that the sensor does not measure... A large vacuum leak could also let unmetered air in the engine.

Or... Another possibility here would be low fuel pressure (bad fuel pump, bad fuel pressure regulator, fuel leak), as not enough fuel for the air would also cause the same lean condition.

It could be that some oxygen sensors are bad...

These conditions are hard to pinpoint exactly unless you have a scanner that can read sensor data (MAF Flow, fuel pressure, oxygen sensor values)...

The first thing I'd do would be to check for cracks or damage in the intake piping... If there is none, then it might be a low fuel pressure issue, or sensor problems...
2helpful
1answer

CHECK ENGINE LIGHT ON , WITH CODE SYSTEM TOO LEAN

Possible failed bank 1 sensor 1 oxygen sensor..
2helpful
2answers
Not finding what you are looking for?

334 views

Ask a Question

Usually answered in minutes!

Top Mercury Experts

ZJ Limited
ZJ Limited

Level 3 Expert

17989 Answers

Thomas Perkins
Thomas Perkins

Level 3 Expert

15088 Answers

Arnie Burke
Arnie Burke

Level 3 Expert

7339 Answers

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

Answer questions

Manuals & User Guides

Loading...