3rd gen Engine/Drivetrain Engine/Drivetrain Modification Discussions for 1999-2003 Models Only (BJ chassis)

OBD-II code: P0171 (lean mix) code: causes?

Thread Tools
 
Search this Thread
 
Old April-4th-2007, 02:08 PM
  #1  
Registered User
Thread Starter
 
majorhavoc's Avatar
 
Join Date: Feb 2007
Posts: 16
majorhavoc is on a distinguished road
OBD-II code: P0171 (lean mix) code: causes?

I have a 2001 Protege LX (the 1.6L). My check engine light came on a few weeks ago, so I invested in a code reader. It pulled the above referenced code. According to the Mazda factory service manual, this code can be triggered by any of the following:

• Misfire
• HO2S (front) deterioration
• HO2S (front) heater malfunction
• PRC solenoid valve malfunction
• Pressure regulator malfunction
• Fuel pump malfunction
• Fuel filter clogged or restricted
• Fuel leakage on fuel line from fuel delivery pipe and fuel pump
• Fuel return hose clogged
• Leakage from exhaust system
• Purge solenoid valve malfunction
• Purge solenoid hoses improper connection
• Insufficient compression

I've cleared the code and it hasn't come back since, so for now I'm treating this as a random event. I am having no drivability problems.

However, if it comes back again, I'll have to start thinking about what the root cause is. Does anyone have any experience about what is the most likely cause/fix for this? Spark plugs maybe?

Many thanks.
majorhavoc is offline  
Old April-5th-2007, 09:00 AM
  #2  
Banned
 
njaremka's Avatar
 
Join Date: Oct 2001
Location: Central New York
Posts: 1,241
njaremka is on a distinguished road
my 2.0 liter ES threw that code, and it was the MAF sensor.
njaremka is offline  
Old April-5th-2007, 09:29 AM
  #3  
Registered User
Thread Starter
 
majorhavoc's Avatar
 
Join Date: Feb 2007
Posts: 16
majorhavoc is on a distinguished road
Originally Posted by njaremka
my 2.0 liter ES threw that code, and it was the MAF sensor.
I was afraid of that. I've read that the MAF sensor is dicey on the Protege. Did you live with the code for a while, or did you replace it right away? Am I harming the engine by ignoring it for a while (the code hasn't yet come back).

How much does a MAF sensor cost? Is it something a home mechanic with more time than money can do?

Thanks again.
majorhavoc is offline  
Old April-5th-2007, 09:42 AM
  #4  
Banned
 
njaremka's Avatar
 
Join Date: Oct 2001
Location: Central New York
Posts: 1,241
njaremka is on a distinguished road
if your engine really is running lean, you might not want to ignore it. possible to cause engine damage. i tried to live with the code while i tried to figure out what the problem was, and the engine ran worse and worse every day. eventually, i had to take it in to the dealer to diagnose the real problem. you might want to do that, just to make sure what the problem is. remember, just because they tell you what the problem is, does not mean they have to be the one to fix it.
njaremka is offline  
Old May-10th-2007, 01:57 PM
  #5  
Registered User
 
Alejo_NIN's Avatar
 
Join Date: May 2007
Posts: 54
Alejo_NIN is on a distinguished road
it could also be exhaust leak before the oxygen sensor, fauty fuel injectors, faulty sparkplugs, faulty MAF sensor.

i had a bank 1 too lean because of a cracked exhaust manifold
Alejo_NIN is offline  
Old May-16th-2007, 06:04 PM
  #6  
Banned
 
Ken@ProtegeGarage's Avatar
 
Join Date: Feb 2004
Location: Grayslake, IL
Posts: 275
Ken@ProtegeGarage is on a distinguished road
MAF sensor, o2 sensor, vacuum leaks, coil packs

my money is on MAF or vac leak
Ken@ProtegeGarage is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dappa1
3rd gen Engine/Drivetrain
9
November-14th-2005 09:40 PM
ShogunProtege
3rd Gen Protege/MazdaSpeed/P5/MP3
5
May-9th-2005 05:43 PM
Jas00x
3rd gen Engine/Drivetrain
15
February-4th-2004 05:52 AM
ColoredDreamsZ
2nd Gen Protege
2
January-8th-2004 10:06 AM
IMPACT
3rd gen Engine/Drivetrain
2
September-4th-2003 10:30 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


Quick Reply: OBD-II code: P0171 (lean mix) code: causes?



All times are GMT -5. The time now is 12:10 AM.