Help With Code P0171 H
Thread Starter
Le Mans Master
Joined: Aug 2006
Posts: 9,987
Likes: 25
From: If opportunity doesn't knock, build a door. South West Florida / Livin' The Dream
St. Jude Donor '12
Help With Code P0171 H
Folks, I've been driving the vette a lot this week since I'm on vacation. Earlier today I shut it off for about 5 min while picking up my grandson and when I restarted the check engine light came on. It hadn't been on previously. I immediately checked to see what code it was throwing and the only code was P0171 H. I cleared it and the check engine light went out and I drove it about 20 more miles and it didn't throw anymore codes.
I checked my list of DTC codes and here's what I found:
P0171 Fuel Trim System Lean Bank 1
Should I be worried or is it a fluke? What should I do next?
Thanks for your help.
I checked my list of DTC codes and here's what I found:
P0171 Fuel Trim System Lean Bank 1
Should I be worried or is it a fluke? What should I do next?
Thanks for your help.
Thread Starter
Le Mans Master
Joined: Aug 2006
Posts: 9,987
Likes: 25
From: If opportunity doesn't knock, build a door. South West Florida / Livin' The Dream
St. Jude Donor '12
May have found the answer to my own question. I'll definatly check the MAF and clean it.
Technical DescriptionSystem Too Lean (Bank 1)
What does that mean? 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 is very similar to P0174, and in fact your vehicle may show both codes at the same time.
Symptoms: You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.
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 SolutionsPossible 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
Here's a link that I book-marked to help in the future.
http://www.obd-codes.com/p0171
Technical DescriptionSystem Too Lean (Bank 1)
What does that mean? 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 is very similar to P0174, and in fact your vehicle may show both codes at the same time.
Symptoms: You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.
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 SolutionsPossible 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
Here's a link that I book-marked to help in the future.
http://www.obd-codes.com/p0171
Last edited by Optimus_C5; Jun 26, 2008 at 08:28 PM.
