P0171 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


OBD-II Trouble Shooting Got a code reader? Find out what your GM car's Check Engine light is trying to tell you (and then turn Check Engine light off).

 
 
 
 
Thread Tools Search this Thread
Old 09-23-2009, 10:43 PM   #1
Retired Senior Admin

Expert Gearhead
Thread Starter
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default P0171

P0171

Description
System Too Lean (Bank 1)

The oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust).


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 could be a vacuum leak downstream of the MAF sensor.
  • Low fuel pressure.
Possible Solutions
  • In the vast majority of cases, simply cleaning the MAF sensor does the trick.
  • Inspect all vacuum and PCV hoses, replace if necessary, touch fittings, if your finger turns black, replace
  • Check for a dirty fuel filter, replace if needed, and proper fuel pressure
  • Check for loose sensors, MAF and IAC. The IAC has a O ring that should be checked.
  • Check intake manifold, injector "O" rings, EGR adapter,
    EGR valve, and EGR feed pipes for vacuum leaks. remove pipe and visually inspect.
  • Inspect EVAP purge valve for proper function.
  • Inspect battery cables for corrosion.
  • Inspect engine grounds.
  • Check exhaust system for corrosion, loose or missing
    hardware.
  • Test fuel pressure, key on, engine off.
Danthurs is offline  
 
 
 

Related Topics
Thread Thread Starter Forum Replies Last Post
P0102, P0171. MAF, Lean Falcon123 1992-1999 10 11-02-2005 03:12 PM
"Service Egnine Soon" -- Eerror Code P0171 coliphage 2000-2005 11 10-19-2005 06:33 PM
DTC P0171 / Fuel Trim Lean... SSEi95 1992-1999 10 10-04-2005 08:40 AM
Trouble code p1640 and p0171 salmanman 1992-1999 4 10-23-2004 04:06 PM
SES light code P0171 Baileyjack 2000-2005 3 08-04-2003 08:46 PM


Tags
obd2, obdii, p0171, p171

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 02:01 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.