Question about 1996 Pontiac Sunfire

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1996 Sunfire, 2.2 Code P0171 bank one too lean

Changes made so far: O2 Sensor, map sensor and air intake control valve, cannot detect any vacuum leaks, plugs and wires are new, firing order correct. new thermostat.
uses fuel like crazy, exhaust smells, after clearing code car runs for a few days, then starts acting up and engine light comes back on,
Also having a hard time clearing the drive cycle in the computer for emissions inspection. 60,000 miles plus a few.

Any help is appreciated! Thanks

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  • 2 more comments 
  • jamonteleone Feb 19, 2009

    Hi 66 chrgr,, no I haven't,,,, what? do you think?

  • jamonteleone Feb 19, 2009

    Thanks, going to try it next,,,, i feel it's something simple or i am missing the basics here at this point.....

    the fuel lines are rusted and need replaced along with it,,,, that's why i havent messed with it just yet. But for now, rubber fuel line and hose clamps will provide another process of elimination.

    Thanks!

  • mike loshbough
    mike loshbough May 11, 2010

    this if clogged will cause a 171 lean code

  • mike loshbough
    mike loshbough May 11, 2010

    did you replace fuel filter?

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5 Suggested Answers

ewashmidas
  • 362 Answers

SOURCE: PO171 error code System too lean bank 1

Here are some possible causes, I would start with anything related to replacing the intake.

Air leaks in intake manifold, exhaust pipes or exhaust manifold
Fuel control sensor is out of calibration
Low fuel pressure (fuel filter clogged, pressure regulator failure)
One or more injectors restricted or pressure regulator has failed
O2 sensors contaminated, deteriorated or has failed
Vacuum hose is disconnected, broken, leaking or loose

Posted on Jan 28, 2009

roedmondson
  • 68 Answers

SOURCE: 2000 CIVIC System too lean Cylinder 3 and 4 misfire Deteced

  1. P0171: This means that the oxygen sensor has detected a lean air-fuel ratio. This can be caused due to a vaccuum leak or a problem in the HO2S circuit or the HO2S (Heated Oxygen Sensor) itself. (Bank one Sensor one). This is commonly located along the exhaust pipe. It could also be a bad Mass Air Flow sensor or a bad Engine Coolant Temperature sensor. Diagnostic checks will be needed to be carried out to be verified though
  2. Well as for the other codes, it means #3&4 cylinders are misfiring. It is a possibility that the P0171 code mite have caused the others to show up. I can be wrong though. But it is a strong possibility. If the air fuel mixtue is too lean indeed, mis-firing will occur, unless it is an actual electronic and not a mechnical problem. By the way, when these codes appear, how is the engine's performance. Does it remain the same or behaves poorly?

Posted on Feb 14, 2009

  • 112 Answers

SOURCE: 2002 Pontac Grand Prix GTP P0171 code engine stumbling at times

Bank 1 is the frt side exhaust manifold (did they say bank 1 sensor 1?),you can start by replacing that sensor,i would check the intake for leaks ,the gm 6cly. are known for bad intake gaskets,you will see oil coming out form the frt or rear of the intake,also check your atifreeze overflow bottle for bronwish sludge,which means that the oil is mixing with the antifreeze.A leaking intake could cause that lean condition.

Posted on Mar 29, 2009

techbuster
  • 5081 Answers

SOURCE: I have a P0171 to lean bank 1 error code

oxygen sensor, vacuum leak, and yes it could most definitly be if you swaped the wires of the firing order accidently you will get a code p0171 Check the tubing going from the air filter to the intake manifold to see if it has come loose. This might account for extra air going into the intake manifold than the computer is aware of. Otherwise it may be due to a faulty(or dirty) MAP/MAF sensor. Another possible cause is from low fuel pressure due to restricted fuel lines or a bad fuel pump.

Posted on Jul 28, 2009

  • 7353 Answers

SOURCE: have p0130 and p0133 codes 98 toyota tacoma

I would check the O2 sensor, and if it checks bad, replace it, and clear the trouble codes. If the light comes back on, you may need to check further. .

Posted on Oct 28, 2009

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Mazda 2000 Error Codes: P0401 P0106 P1170 P0171


Hi there:

DTC P0401 - Insufficient EGR Flow
EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor EGR (DPFE). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 code means that OBD detected an insufficient amount of EGR.



A code P0401 most likely means one or more of the following has happened:
The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
There is a blockage in the EGR (tube), most likely carbon buildup
The EGR valve is faulty
The EGR valve may not be opening due to a lack of vaccuum


Possible Solutions:
In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.


Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
Clean out the EGR valve and/or tubing to remove deposits
Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
Replace the DPFE sensor (with a good quality / OEM one)
Replace the EGR valve





DTC P0106 - MAP/Barometric Pressure Circuit Range/Performance Problem
The Powertrain Control Module (PCM) uses the Manifold Absolute Pressure Sensor (MAP) to monitor engine load. (NOTE: Some vehicles have a Barometric Pressure (BARO) sensor that is integral to the Mass Air Flow (MAF) sensor and do not have a MAP sensor. Other vehicles have a MAF/BARO and a redundant MAP sensor where the MAP sensor functions as a backup input in case of MAF failure.) The PCM supplies a 5 Volt reference signal to the MAP sensor. Usually the PCM also supplies a ground circuit to the MAP sensor as well. As the manifold pressure changes with load, the MAP sensor input informs the PCM. At idle the voltage should be 1 to 1.5 Volts and approximately 4.5 Volts at Wide Open Throttle (WOT). The PCM looks for any change in manifold pressure to be preceded by a change in engine load in the form of changes in throttle angle, engine speed, or Exhaust Gas Recirculation (EGR) flow. If the PCM doesn't see any of these factors change while detecting a rapid change in MAP value, it will set a P0106.


A P0106 could be caused by:
Bad MAP sensor
Water/dirt intrusion affecting MAP sensor connector
Intermittent open in the reference, ground, or signal wire for the MAP sensor
Intermittent short in the reference, ground, or signal wire for the MAP sensor
Ground problem due to corrosion causing intermittent signal problem
A break in the flexible air intake duct between the MAF and the intake manifold
Bad PCM (do not assume the PCM is bad until you've exhausted all other possibilities)

Possible Solutions: Using a scan tool, watch the MAP sensor value with the key on, engine off. Compare the BARO reading with the MAP reading. They should be roughly equal. The voltage for the MAP sensor should read approx. 4.5 volts. Now start the engine and look for a significant drop in the MAP sensor voltage indicating the MAP sensor is working.

If the MAP reading doesn't change perform the following:

With the Key on, engine off, disconnect the vacuum hose from the MAP sensor. Using a vacuum pump, pull 20 in. of vacuum on the MAP sensor. Does the voltage drop? It should. If it doesn't inspect the MAP sensor vacuum port and vacuum hose to manifold for a restriction of some kind. Repair or replace as necessary.
If there are no restrictions, and the value doesn't change with vacuum, then perform the following: with the Key on and engine off and the MAP sensor unplugged, check for 5 Volts at the reference wire to the MAP sensor connector with a Digital Voltmeter. If there is none, check for reference voltage at the PCM connector. If the reference voltage is present at the PCM connector but not the MAP connector, check for open or short in the reference wire between MAP and PCM and retest.
If reference voltage is present, then check for existing ground at the MAP sensor connector. If it isn't present then repair open/short in the ground circuit.
If ground is present, then replace MAP sensor.


DTC P0171 - System Too Lean (Bank 1)
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.



This 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.


You'll want to also read our article on short and long term fuel trims to help understand the operation of the engine. Note: This DTC is very similar to P0174, and in fact your vehicle may show both codes at the same time.


A code P0171 may mean that one or more of the following has happened:
The MAF (Mass Air Flow) Sensor is dirty or faulty
Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak downstream of the MAF sensor
Possible cracked vacuum or PCV line/connection
Faulty or stuck open PCV valve
Failed or faulty oxygen sensor (bank 1, sensor 1)
Sticking/plugged or failed fuel injector
Low fuel pressure (possible plugged/dirty fuel filter!)
Exhaust leak between engine and first oxygen sensor


Possible Solutions: A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks fix the problem. If you're on a tight budget, start there, but that may not be the fix for certain. So, possible solutions include:


Clean the MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace/repair as required
Inspect all hoses and connections in the air intake system
Inspect and/or test the intake manifold gaskets for leakage
Check for a dirty fuel filter and proper fuel pressure
Ideally you'll want to monitor short and long term fuel trims using an advanced scan tool
If you have access, you may want to run a smoke test




DTC P1170 - HO2S Bank 1 Sensor 1 Circuit Fixed (Bank 1 Sensor 1)

Most likelly cause is Aging Heated Oxygen Sensor 1/1 Front RH. Hook up a Scantool and monitor sensor responce. You can also check resistance of Heater on terminal D and C for about 6ohms.

As usual check for any vacuum/exhaust leaks. Maybe check fuel pressure and fuel filter.





Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

Aug 02, 2012 | 2000 Mazda Protege

2 Answers

My Toyota Camry 96 isn't starting. New battery the alternator and starter are working properly and there are new spark plugs . The engine is turning over and it's getting fuel but it just doesn't start....


Faulty MAP or MAF sensor, EGR valve stuck open, spark plug wires don't match firing order, large vacuum leak to intake manifold, very dirty fuel injectors, idle air control valve defective, poor compression in cylinders due to incorrect valve timing or leaking fuel injector o-ring seals.

Feb 10, 2011 | 1998 Toyota Camry

2 Answers

1999 ford ranger 4x4 4.0L motor is skipping replaced camshaft sensor,crankshaft sensor,new coil pack,new plugs,wires,and replaced mass air flow sensor,now its still skipping and codes pulled are showing...


P1151 means a lean bank 2 O2 sensor
P1152 Means a rich bank 2 O2 sensor
P1309 Means miss fire detected
I would check your fuel injector for fouling
When they foul the will develop a drip
Causing a fuel fluctuation that will have O2 sensors reporting rich and lean voltage changes
This causes the pcm to adjust injector pulses making them shorter and longer.
causing more fuel or less fuel.
From this condition you may see plug fouling.
Also check for leaking or faulty fuel pressure regulator or restricted return line.
Most of the time it wont be a bad O2 sensor the O2 sensor is just doing its job.
You also have already changed the plugs and Map so there already out of the way.
If this helps please give me some feed back
Hope this works for you FixYa

Jan 29, 2011 | 1999 Ford Ranger SuperCab

2 Answers

Po108 service code


Hi,
OBD II Fault Code
  • OBD II P0108
Fault Code Definition
The Manifold Absolute Pressure Sensor/Barometric Pressure Sensor measures the rise and fall of the air pressure inside the Intake Manifold. This provides critical data needed for the Power Train Control Module (PCM) to control the Air Fuel Ratio, the Ignition Spark Timing, and many components of the Emissions Control Systems. The Manifold Absolute Pressure/Barometric Pressure Sensor converts the Intake Manifold air pressure into a voltage that is high when the Intake Manifold air pressure is high and low when the Intake Manifold air pressure drops to a vacuum. The P0108 code indicates a high voltage input from the Manifold Absolute Pressure Sensor/Barometric Pressure Sensor to the Power Train Control Module.
Symptoms
  • Check Engine Light will illuminate
  • In many cases, no abnormal symptoms may be noticed
  • In some cases, the engine may be hard starting and/or get poor fuel economy
  • In some cases, noticeably poor engine performance may occur
Common Problems That Trigger the P0108 Code
  • Manifold Absolute Pressure Sensor/Barometric Pressure Sensor is defective
  • Intake Manifold vacuum leaks
  • Faulty or corroded Manifold Absolute Pressure Sensor/Barometric Pressure wiring or connections
Common Misdiagnoses
  • Manifold Absolute Pressure Sensor/Barometric Pressure Sensor is replaced when the real cause is an Intake Manifold vacuum leak
  • Manifold Absolute Pressure Sensor/Barometric Pressure Sensor is replaced when the real cause is a stuck-open EGR Valve
  • Manifold Absolute Pressure Sensor/Barometric Pressure Sensor is replaced when the real problem is a defective Idle Air Control Motor, which causes a very low engine idle

Jan 26, 2011 | Mazda MPV Cars & Trucks

1 Answer

I changed all three coils and plugs and wires. I also verified the correct firing order as well as the plkug placement. the engine will turn over and hit but will not idle or accept throttle ,after several...


You changed coils, plugs n wires, but did you check if you have spark? your ignition module could be faulty. Don't forget to clean or replace plugs before trying something else and while you'r at it check your firing order one more time.

Also check for:

Vacuum leaks, uneven or low cilinder compression, ignition timing, dirty air filter, spark plug gap, idle air control selenoid sticking, EGR valve stuck open and faulty map sensor.

I am curious on how all this started!! When was the last time the car ran fine?

Good Luck buddy!!

Mar 10, 2010 | 1995 Chevrolet Monte Carlo

1 Answer

Getting a code 172 rich fuel cond 1.9 liter it has had a new cat and both o2 sensors it has had a map sensor and the evap purge valve checks out. No external vac leaks are detected it has had new plugs and...


you might want to check the intake for leaks-let the engine run-while running spray some brake cleaner around the intake-if the engine boggs down or dies that means your intake gasket is leaking and needs replaced-this is very common

Feb 17, 2010 | 2001 Saturn SC

1 Answer

More fuel consumpion


No codes? Checklist: MAF: Mass Air Flow Sensor, MAP: Manifold Absolute Pressure Sensor, Engine Valves/Low cylinder compression, Fuel Injectors, Fuel Pressure, Tire pressure, vacuum leak(s), PCV: Polution Control Valve, Purge Control Solenoid Valve PCSV stuck open/leaking, Intake Air Hose leaking, Engine Coolant Temperature Sensor, Intake Air Temperature Sensor, etc. etc. etc..
Go to http://www.hmaservice.com/ and register (vehicle by VIN). Afterward, you'll have access to technical information (manuals, wiring diagrams, service bulletins, etc) about your vehicle.

Apr 01, 2009 | 2001 Hyundai XG300

1 Answer

1995 Ford Bronco 172 EGO not switching lean bank1- jerks when run


Have u checked for vacuum leaks or poss leaking EGR valve? use carb spray around the upper intake manifold where it bolts to the lower manifold, spray vacuum lines where they are connected to the engine vacuum ports, the idle speed will change if u hit a leak, as far as the EGR valve goes see if it gets hot at idle, if it does it is leaking, if all checks ok replace the O2 sensor, but i suspect u will find a leak at the upper intake plenum.

Dec 06, 2008 | 1995 Ford Bronco

1 Answer

2005 jeep liberty diesel code # p0101 map- sensor out of range what is map


The MAP sensor (MANIFOLD ABSOLUTE PRESSURE) changes voltage or frequency as intake manifold pressure changes (air flow increases or decreases). The engine's computer uses the reading to advance or ****** engine timing. On older, non-fuel injected engines the vacuum advance on the distributor did basically the same thing.
The MAP sensor also works with other sensors on the Jeep engine, specifically the Throttle Position Sensor (on the throttle body) and Crank Position Sensor (on the transmission bell housing) to control other fuel flow and ignition timing functions.
If you're having problems with the MAP sensor, or are getting a Check Engine light and code for the MAP sensor keep in mind that other problems may cause that error code.
Bad vacuum hoses, vacuum leaks, bad EGR valves, intake manifold leaks, clogged air filter can all affect the MAP. sensor. To know for sure all the other sensors should be checked for correct voltage and perimeters
Also, if you have done any mods to the engine, especially intake, exhaust and ignition mods you may get an error code for the MAP or incorrect reading and a resulting loss in power or increased fuel usage.
The map sensor is easy to change with a couple screws off the Throttle body.. The part the air inters (the air breather). Buy one from the auto parts store if your sure that is the problem and just replace it..There is no adjustments to it...

It really sounds to me that you have a small vacuum leak in a line somewhere.You can try spraying the motor vacuum lines with soapy water with the vehicle running to find a leak. Also listen and feel under the dash for leaks and hissing sounds.
Hope this helps.......

Oct 31, 2008 | 2005 Jeep Liberty

1 Answer

1993 chev lumina euro 3.1 "t"


recheck valve adjustment and timing as well as vacuum leaks

Aug 06, 2008 | 1996 Chevrolet Lumina Mini

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