Engine Code P0171 (Full Version)

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Engine Code P0171

  

98gstspy -> Engine Code P0171 (7/14/2007 10:37:33 PM)

#P0171- According to the book it means "System adaptive feul too lean (bank 1)".How Would I go about fixing this code? the only Mod I have on my car @ this time is a K&N intake system. That is all if any body can tell me how to fix it that would be great. I also have a new Greddy upper/lower I/C pipes and a AEM Fuel Rail that I have not had time to put on yet

  
Dusty Eclipse -> RE: Engine Code P0171 (7/14/2007 10:40:22 PM)

Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust).

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 (K&N, etc.) can cause the MAF to become dirty if the filter is over-oiled
There could be a vacuum leak downstream of the MAF sensor.

My guess, btw, is the first one.

98gstspy -> RE: Engine Code P0171 (7/14/2007 10:43:26 PM)

Would putting on bigger injectors help me out? I was looking at some that flow 400cc from summit racing

Dusty Eclipse -> RE: Engine Code P0171 (7/14/2007 10:45:38 PM)

What the hell? No. That wont help. You need to clean your MAF (most likely) use brake cleaner or something like it. Just spray the bitch down.

98gstspy -> RE: Engine Code P0171 (7/14/2007 10:48:26 PM)

What I ment with the injectors is would that be a good way to some more power out of the engine w/out having to go to a bigger fuel pump or a new pressure regulator. Would I have to modify the ECU like they are telling me or would I still be in safe conditions

Dusty Eclipse -> RE: Engine Code P0171 (7/14/2007 10:52:04 PM)

If you get larger injectors, Id suggest also installing a larger fuel pump... i.e.-Walbro 255. But none of those things will rid you of your problem. Not efficiently anyway. The best way to get a good amount of power outta that is by installing a new turbo. Like a 16g or a hybrid. Its likely that your car has a t25... and those things... well... they aint the best.

98gstspy -> RE: Engine Code P0171 (7/14/2007 10:57:32 PM)

Would those be big enough or should I go bigger. It is a stock 2g turbo that I most likly wont change and if i do it wont be for a long time. Im really just looking for somthing that will get me going Faster w/out having to change major parts ie-turbo. by the way thank you for your help on this little problem, my first car and im trying to make it a nice one.

Dusty Eclipse -> RE: Engine Code P0171 (7/14/2007 11:05:11 PM)

The turbo isnt that hard to change... no harder than redoing your fuel system (IMO) time wise anyway. Besides, more fuel w/o more air will just give you a NEW engine code showing a RICH condition. Youll need a few things first anyway, before you can just change out your injectors. Stock the car has 450s... as far as I know, so 400 wouldnt help you... it would impede you.
Example - Im running 650s... but Ive also got a t3/t4. Thusly it sort of necessitates larger injectors.

98gstspy -> RE: Engine Code P0171 (7/14/2007 11:14:37 PM)

Do you have any suggestions on how I can make it faster w/out having to change out my turbo?

silvercoupe97 -> RE: Engine Code P0171 (7/14/2007 11:14:37 PM)

quote:

ORIGINAL: 98gstspy

#P0171- According to the book it means "System adaptive feul too lean (bank 1)".How Would I go about fixing this code? the only Mod I have on my car @ this time is a K&N intake system. That is all if any body can tell me how to fix it that would be great. I also have a new Greddy upper/lower I/C pipes and a AEM Fuel Rail that I have not had time to put on yet
You may have a boost leak or your MAF sensor is caked like Dusty stated.
Don't put that fuel rail on...there's no need for it at this point, the stock fuel rail flows a lot and isn't needed until you pass at least 500chp.
quote:

ORIGINAL: 98gstspy

Would putting on bigger injectors help me out? I was looking at some that flow 400cc from summit racing
You should have 450cc injectors in there now.  That's stock.
quote:

ORIGINAL: 98gstspy

What I ment with the injectors is would that be a good way to some more power out of the engine w/out having to go to a bigger fuel pump or a new pressure regulator. Would I have to modify the ECU like they are telling me or would I still be in safe conditions
Bigger fuel injectors means you will need a bigger pump or else you're just wasting your money on a half ass fuel system...don't forget an adjustable fuel pressure regulator also. 
You will need some sort of fuel management if you upgrade your fuel system + turn up the boost pressure.

quote:

ORIGINAL: 98gstspy

Would those be big enough or should I go bigger. It is a stock 2g turbo that I most likly wont change and if i do it wont be for a long time. Im really just looking for somthing that will get me going Faster w/out having to change major parts ie-turbo. by the way thank you for your help on this little problem, my first car and im trying to make it a nice one.
The t25 runs out of breath around 5500 RPMs, so your only real hope to gain a little bit is to do the free mods, get a 1G bov, and wait until you save up some money to upgrade the turbo and fuel system.
...and no, larger injectors on a t2g turbo won't do you any good.  If anything, you'll only run more rich which will hinder performance.
Follow this upgrade path..
http://www.roadraceengineering.com/2gupgradepath.htm
..and don't put anything in half ass.  Do a system all at once and not piece by piece.  I don't mean that you can't buy piece by piece, I mean don't put them into your car in that way.

  

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