Engine Code P0171
 

#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 thatI have not had time toput on yet

RE: Engine Code P0171
 

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.

RE: Engine Code P0171
 

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

RE: Engine Code P0171
 

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.

RE: Engine Code P0171
 

WhatI 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. WouldI have to modify the ECU like they are telling me or wouldI still be in safe conditions

RE: Engine Code P0171
 

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.

RE: Engine Code P0171
 

Would those be big enough or shouldI 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.

RE: Engine Code P0171
 

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.

RE: Engine Code P0171
 

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.
You should have 450cc injectors in there now. That's stock.
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.

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.

RE: Engine Code P0171
 

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