Code P0171 help

[RallyeRedSi]

I got CEL p0171 (system too lean Bank 1)and im tyring find solutions on how to get rid of it, i cleaned otu the injectors and the MAF and its still on, i heard about changing the 1st o2 sensor, will that fix it, how about cleaning thre EGR? Can i get i fixed under warranty? Thanks alot for the help

 

[BlueBeast22]

Check your vaccum hoses. I have a friend who is throwing the same CEL code and he has some vaccum loss issues. Check all your couplings, and vaccum lines for any leakage!

 

[Rio Racer]

In hyundai tiburons every one throws that code if you have an intake and oil from the intake filter gets on the MAF sensor. This is remedied by purchasing CRC electronics cleaner and spraying the MAF needle and resetting the ECU by disconnecting the negative terminal on the battery.

 

[RallyeRedSi]

i cleand the MAF today and had the code cleared and it came back on in minutes

 

[Rio Racer]

Damn I didn't see that in your original post.

 

[Panzozo]

i cleand the MAF today and had the code cleared and it came back on in minutes

Take it back to the dealer if you still under warranty. I had the same problem, throwing P0171. Turns out it's the wastegate actuator. They replaced it for free.

 

[RallyeRedSi]

hmmm maybe i will do that

 

[dirtysouth_msp]

P0171 means the system is too lean. This is most commonly attributed to a vacuum leak or a leak in the intake tract after the MAF in the MSP. Check all clamps on the intake. Check all vacuum lines and test your wastegate actuator. Testing of vac lines and WGA is most easily done with a handheld vacuum pump, unless you have a smoke machine at your disposal, which most people don't. If the are any vac lines or the WGA do not hold vacuum, then that is where you should start. The Maf could cause this code to appear also. If the MAF is dirty or malfunctioning, it will not read the air passing through it accurately. It usually underestimates air flow, this causes the ECU to inject amounts of fuel that are inadequate for the actual flow, causing a lean condition.

 

[y0sky]

Can you explain more of what a handheld vacuum pump is and how you use it to test, like how will the waste gate actuator act with the pump. I too am having problems with this code.

 

[ZenProtege]

Think of it like it's an air pump for your tires that has a pressure guage on it,... that might be better described as being like an air pump used for bicycles. It allows you to pressurize air on a vac line to say a WG actuator, vics solenoid, VCTS soleniod / actuator, etc, and see if there is a leak in the actuator or line itself. You just monitor the line's pressure by looking at the guage to see if it's holding steady or losing pressure

 

[dirtysouth_msp]

Yeah, that's the idea, but instead of applying pressure it applies vacuum. If you apply vac to the WGA and it does not hold, then that means that the diaphram is leaking and you need a new WGA. It is also possible that the WGA will not leak under vacuum, but will leak under pressure. Some vac pumps are reversible so that you can apply pressure also. If you do not have access to one of these, you can just try to blow air through the line with your lungs. Unless you are some kind of freak you should not be able to create 6-8lbs of pressure, so if you can blow air freely through the line the WGA is bad. Also, you should probably attach a new piece of vac line directly to the WGA to test it.

 

[sk8er_jason04]

95% of the time is a simple vacuum leak.. I had this problem not to long ago and it was because of the waste gate actuator. The vacuum diaphram inside the waste gate was totally wasted. Use a hand held pump and check the vacuum lines. if your runnin 10 - 18 psi then clamp the hose coming off the waste gate and i bet you it jumps to 25 psi.

 

[y0sky]

Yeah. Did that. I will be getting the wastegate actuator fixed soon. I hit 18psi the other day. Man what a feeling. Wish it wasnt so dangerous on stock internals.