P0171 code
Thread Starter
Drifting
Joined: Jan 2007
Posts: 1,460
Likes: 38
From: Broken Arrow Oklahoma
P0171 code
I had my engine light come on today after a spirited run. P0171 shows that bank 1 is running too lean. I had had my engine light come on last week for my O2 sensor on that same side. A header leak burned up the sensor. So I replaced that upstream O2 sensor. Everything checked out fine after replacing that sensor. I rerouted the sensor so it was away from the header and I ordered a new gasket for the header to fix the slight leak. This is my first spirited drive since doing that. Is this new code related to replacing that O2 sensor or something else? What do you guys think?
Thread Starter
Drifting
Joined: Jan 2007
Posts: 1,460
Likes: 38
From: Broken Arrow Oklahoma
I have ordered that new lead donut gasket. I haven't replaced it so there is still that leak there. It is right in front of the converter. Would a leak right there cause thise code?
Burning Brakes
Joined: Aug 2008
Posts: 802
Likes: 6
From: Oro Valley AZ
You may want to try using a wideband sensor to check both banks of the engine at the muffler. If your AFR is Okay you know its one of the O2 sensors again. Then, you have to ask why the repeated failure. What brand headers are you using?
Moderator emeritus
Joined: Jun 2001
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From: Jacksonville Florida BWO Dayton, Cincinnati, Bloomsbury NJ, Cincinnati
2015 C7 of the Year Finalist
Quote from step 6 of this:
http://www.ls2.com/boggs/dtcs/DTC%20P0171.htm
Visually/physically inspect the following items:
* Bank 1 exhaust leaks, missing or loose exhaust hardware.
* Bank 1 HO2S 1 is installed securely and the electrical connector not contacting exhaust system or ignition wires.
* Engine mechanical failure. Refer to Base Engine Misfire Diagnosis in Engine Mechanical 5.7L.
* Vacuum leaks that will only affect bank 1, such as the intake manifold, the injector O rings, etc.
So, yes, air/vacuum leaks will throw this code.
Elmer
http://www.ls2.com/boggs/dtcs/DTC%20P0171.htm
Visually/physically inspect the following items:
* Bank 1 exhaust leaks, missing or loose exhaust hardware.
* Bank 1 HO2S 1 is installed securely and the electrical connector not contacting exhaust system or ignition wires.
* Engine mechanical failure. Refer to Base Engine Misfire Diagnosis in Engine Mechanical 5.7L.
* Vacuum leaks that will only affect bank 1, such as the intake manifold, the injector O rings, etc.
So, yes, air/vacuum leaks will throw this code.
Elmer
