2011 Tahoe p0171 & p0174 codes

[MACHO]

Check engine light came on today. Pulled codes p0171 & p0174. Only 17k miles, so still under warranty obviously. Been running a Airaid MIT intake for 5k+ miles and just added the dry filter 2k miles ago. Had my BB tune for 5k+ miles. And have used 3/4 of the full tank of gas since wife filled it up last.

I searched the forums and found this was a lean code and typical of a vacuum leak but most people seemed to be having this with their NBS's so my question is:

(1) could it be the gas cap wasn't secured fully?

(2) would I be okay to clear the code and see if it comes back? or should I just leave it alone until I take it to the dealer?

 

[Goodinblack]

Re: 2011 Tahoe p0171 & p0174 codes

So it does pull codes.

I would just take it to the stealership.

Do not clear it. Because if the codes for not come back for a while and you take it to them.....they may not be able to replicate the code. So they send you away and tell you to keep driving.

Then the code comes back at the worst moment.

I hope they are not concerned about the tune being there though.

 

[Regency]

A code P0171 or P0174 indicate the engine is running lean. This means there is too much air and/or not enough fuel. You can confirm the engine is running lean by looking at Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). Normally, STFT and LTFT should be plus or minus 8 from zero. If STFT and/or LTFT are more than about +10 or higher, it indicates the engine is running LEAN. Negative numbers (-10 or more) indicates the engine is running RICH.

A lean fuel condition can be caused by:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)

______________________________--



Causes

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 Solutions

Possible solutions include:


In the vast majority of cases, simply cleaning the MAF sensor does the trick. 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 if necessary
Check for a dirty fuel filter and proper fuel pressure

 

[MACHO]

2011 Tahoe p0171 & p0174 codes

Okay nevermind!! So as soon as I posted this, I went out to check the MAF and hoses on the intake while I awaited a response. I discovers the whole effing intake tube had popped of the throttle body!

 

[Goodinblack]

Re: 2011 Tahoe p0171 & p0174 codes

Marcus is on it tonight.

 

[MACHO]

2011 Tahoe p0171 & p0174 codes

I repositioned the intake tube. (I think I had it positioned so it was a little torqued on the air box side and was pulling it away from the throttle body) Then retorqued everything down nice and tight

---------- Post added at 07:43 PM ---------- Previous post was at 07:41 PM ----------

Thanks Marcus. I appreciate the copy and paste I had read that already online and it want making sense for how new the Tahoe was, which is why I thought it might be something stupid like the gas cap?

---------- Post added at 07:44 PM ---------- Previous post was at 07:43 PM ----------

So it does pull codes.

I would just take it to the stealership.

Do not clear it. Because if the codes for not come back for a while and you take it to them.....they may not be able to replicate the code. So they send you away and tell you to keep driving.

Then the code comes back at the worst moment.

I hope they are not concerned about the tune being there though.

That's the best thing about the AutoCal is I can switch it back to stock anytime I need to take it to the dealer

 

[Goodinblack]

Re: 2011 Tahoe p0171 & p0174 codes

Cool Bro.

 

[Blazed]

2011 Tahoe p0171 & p0174 codes

This same exact thing happened to me the other day lol.

 

[blairian]

Re: 2011 Tahoe p0171 & p0174 codes

Also be careful if you keep getting those codes. If the engine is running too lean you risk serious damage to it...

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