Threw a code PO171 - Subaru Enthusiasts Car Club of the Sierras

ddub · 2007-01-26, 09:49 AM

This code is lean running condition. I wasn't stepping on it when it came on. My car is at 60000 miles now, its due to get the spark plugs changed but i don't know if that would cause the problem. Should i try cleaning the MAF? (What should i use to clean it, WD-40) It never threw this code before and i've been running a custom tuned AP for a while. I read in another thread that someone had one of there recirc hoses come loose, which cause the problem. Others said that it could be caused by a boost leak, but boost is fine. Any idea's???

Thanks, Dave

MikeK · 2007-01-26, 09:55 AM

Start reading this link!

sperry · 2007-01-26, 10:26 AM

And don't use WD-40 on a MAF!!! WD-40 is a lubricant, not a cleaner. Pick up some CRC MAF cleaner from just about any Kragen.

MPREZIV · 2007-01-26, 12:46 PM

That writeup Mike posted is all good info!

ddub · 2007-01-26, 04:30 PM

that is a good post. I have a short ram intake and that never caused a problem before. I checked all connections but can't find any leaks. For now, i just used the AP to reset the ECU. If it comes back on, i know that there is a problem somewhere. The engine runs fine, no changes in performance.

sperry · 2007-01-26, 04:34 PM

Quote:

Originally Posted by ddub

that is a good post. I have a short ram intake and that never caused a problem before. I checked all connections but can't find any leaks. For now, i just used the AP to reset the ECU. If it comes back on, i know that there is a problem somewhere. The engine runs fine, no changes in performance.

We've noticed some CELs that seem to be due to altitude up here in Reno. Car gets tuned on a dyno in the Bay... runs great... comes up the mountain, and bam CEL for no apparent reason. Of course the car's I've seen this on all run great... but they do have a CEL.

On the other hand. My car seems to learn bad habits up here at altitude requiring me to reset the ECU frequently to fend of brutal hesitation that the ECU learns. But that doesn't seem to be an altitude problem... I think it's 'cause the ECU is learning to pull timing due to all the oil I get blowing into my intake from the block breathers.

2007-01-26, 09:49 AM	#1
ddub EJ22 Join Date: Aug 2005 Location: Reno, NV Posts: 110 Car: 04 wrx, bunch of mods	Threw a code PO171 This code is lean running condition. I wasn't stepping on it when it came on. My car is at 60000 miles now, its due to get the spark plugs changed but i don't know if that would cause the problem. Should i try cleaning the MAF? (What should i use to clean it, WD-40) It never threw this code before and i've been running a custom tuned AP for a while. I read in another thread that someone had one of there recirc hoses come loose, which cause the problem. Others said that it could be caused by a boost leak, but boost is fine. Any idea's??? Thanks, Dave

2007-01-26, 10:26 AM	#3
sperry The Doink Real Name: Scott Join Date: Nov 2002 Location: Portland, OR Posts: 20,335 Car: '09 OBXT, '02 WRX, '96 Miata Class: PDX/TT-6 The way out is through	And don't use WD-40 on a MAF!!! WD-40 is a lubricant, not a cleaner. Pick up some CRC MAF cleaner from just about any Kragen. __________________ Is you is, or is you ain't, my con-stit-u-ints?

2007-01-26, 12:46 PM	#4
MPREZIV Token Real Name: Le Stig Afrique? Join Date: Jun 2005 Location: sitting next to a big yellow box Posts: 3,589 Car: 2001 Impreza 2.5 RS Class: 05 TDSP No, I won't work on your car. F your car*	That writeup Mike posted is all good info! __________________ "...these condoms have a topical anesthetic to reduce sensitivity, so you can last longer. What a paradox. You can't feel a thing, but you can f*ck for HOURS..."

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2007-01-26, 09:55 AM	#2
MikeK Captain Turbo Join Date: Feb 2004 Location: Reno Posts: 3,318 Car: 05 STi	Start reading this link!

2007-01-26, 04:30 PM	#5
ddub EJ22 Join Date: Aug 2005 Location: Reno, NV Posts: 110 Car: 04 wrx, bunch of mods	that is a good post. I have a short ram intake and that never caused a problem before. I checked all connections but can't find any leaks. For now, i just used the AP to reset the ECU. If it comes back on, i know that there is a problem somewhere. The engine runs fine, no changes in performance.