2001 bonneville po101 maf code Replaced MAF ,MAP (came apart upon removal, pcv (clooged),intake man & gasket (it was cracked),cleaned TB, Cleared the codes.After driving 15 min had a few stutters and light came back on????? Could the temperature sensor or coolant level trip this code without tripping a temp code? I read that the pcm measures air flow by temp. Does the pcm need to be reflashed? Any suggestions are welcome.

Possible solutions include: Inspect all vacuum and PCV hoses, replace if necessary 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 fuel lines for cracks, leaks, or pinches Check the fuel pressure at the fuel rail Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced. Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)

Read more at: http://www.obd-codes.com/p0175
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the following information courtesy of obd .com 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

Read more at: http://www.obd-codes.com/p0171
Copyright © OBD-Codes.com

Hi there:

DTC P0174 - System Too Lean (Bank 2) This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.

A code P0174 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 2, 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

On V6/V8/V10 engines, Bank 2 is generally the side of the engine that doesn't have cylinder #1.

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.

Hi there:

DTC P0174 - System Too Lean (Bank 2) This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.

A code P0174 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 2, 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

On V6/V8/V10 engines, Bank 2 is generally the side of the engine that doesn't have cylinder #1.

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.

Hi there:

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. 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


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.

CHECK THE AIR INTAKE TUBE FOR TEARS OR LEAKS. A LARGE VACUUM LEAK WILL CAUSE THIS.

Hi Dawn.

I don't believe that your MAF has ever been the root cause of the problem to begin with. They don't often fail on their own and especially after only a month. If it is due to an electronic problem then it will be instant. The only other cause is the MAF getting so coated with debris or chemicals that it makes the diodes break. It can get dirty from ineffective air filtering or from getting carbon buildup. Seeing that you needed to have the EGR valve replaced, carbon buildup could be a likely cause. It is a common cause for failure of an EGR valve and simply replacing it won't clean up what's left elsewhere in the system like the throttle body...right where your MAF is mounted.

Here is what I want you to do with your car. Do not take it back to the same garage for any of this, you can easily do most of it yourself. They apparently don't know or don't care anyway, get it out of there or give them specific written instructions what to do with it.

Remove the air intake box and throttle body inlet duct and clean it. Remove throttle body. Clean the throttle intake plenum and bore inlet until absolutely spotless. Replace throttle body gasket with an oil-impregnated one that is trimmed back to fit slightly larger than the throttle opening and DOES NOT have the cutouts for the coolant paths. Next, remove the MAF. Clean it with isopropyl alcohol, WITHOUT pressure such as with an aerosol can. It will bend or break the diodes. Allow to dry.
Remove the IAC valve from the throttle body. Clean it, replace the gasket if worn. Use a toothbrush if it's very dirty, I suspect it is. Do the same thing to the mounting hole for the IAC valve. Clean the throttle body bore and plate, from both ends until spotless.

Mount throttle body back on to new gasket. Replace PCV valve.

Replace all spark plugs with copper core Autolite 605's. They are one heat range cooler than stock; it will help your GTP run better especially on those hot days.

Then run only premium fuel in it. I recommend Shell 93. The brand is recommended; high octane is required.

You could be right but before going to all that trouble of replacing the intake gasket take a close look at the MAF (Mass Air Flow) sensor. Also look for a vacuum leak downstream of the MAF sensor. The MAF sensor may be dirty especially if you are using an "oiled" air filter and it was over oiled. Remove the MAF sensor and clean it with electronic cleaner. Make sure it is dry before reinstalling. If it is damaged, replace it. Also replace the fuel filter as a partially clogged filter has been know to set this code on some vehicles. Check all vacuum hoses and replace as necessary.

I also don't know of a differential pan gasket, just transmission gasket. I'm surprised a 'code' would be generated for this anyway. The MAF sensor is in the air intake hose, between the air cleaner and engine. It can be cleaned with MAF cleaner, found at auto parts store. If not available, use electronic parts cleaner to spray clean. Remove MAF sensor, spray clean and let dry, replace.

Check vacuum hoses to MAP sensor. They can get porous after a while. Also check hose to EGR valve.