Too Lean!!

[4reak]

My check engine light has been coming on, and i go to the local autozone and use the obd reader to see whats up. it says "system too lean", and it has over and over again now. does anyone know why this happens, or what it means? can someone help me out so that the light deosnt come on anymore? thanks in advanced.

 

[Supra725]

From what i understand. I think is that the air and fuel ratios maybe a little bit slow.

Correct me if I'm wrong.

 

[Greedy]

Code

Do you know what the code number is? (PO171 - PO172 etc...)

 

[gapboi210]

Wouldn't an O2 sensor contribute to telling the computer how rich/lean it is running so that the ECM can compensate?

 

[tomhaney1]

Wouldn't an O2 sensor contribute to telling the computer how rich/lean it is running so that the ECM can compensate?

That or your MAF. Try cleaning the MAF and resetting the system. Could actually be a fuel delivery issue as well. Might want to check your injectors...

 

[4reak]

That or your MAF. Try cleaning the MAF and resetting the system. Could actually be a fuel delivery issue as well. Might want to check your injectors...

I'm sorry, but I'm not following the lingo. What is MAF? and yes the code is p171. The autozone guy told me its nothing to worry about and to just delete it and foget about it. But its on again, so I think I dont have the option to just forget about it.

 

[rearviewmirror]

Try disconnecting your battery for a few minutes to reset the ECU as well, also you didn't post if you have any kind of intake or airbox mods.

 

[tomhaney1]

I'm sorry, but I'm not following the lingo. What is MAF? and yes the code is p171. The autozone guy told me its nothing to worry about and to just delete it and foget about it. But its on again, so I think I dont have the option to just forget about it.

My bad, Mass Air Flow Sensor. It reads the amount of air coming in to the vehicle and adjusts fuel delivery, ignition, and transmission shifting.

 

[4reak]

My bad, Mass Air Flow Sensor. It reads the amount of air coming in to the vehicle and adjusts fuel delivery, ignition, and transmission shifting.

Thanks for your time, could you possibly tell me how to do that? like a walk through preferably.

Try disconnecting your battery for a few minutes to reset the ECU as well, also you didn't post if you have any kind of intake or airbox mods.

I havent even thought to disconnect the battery. and i dont have any intake or airbox mods, unless the previous owner did them, but i highly doubt that. he used the rig only to tackle the concrete jungle of his sons daycare. my rig is (to my knowledge) as stock as it gets.

Thanks guys, this site is really helpful, and i really do appreciate the responses and advice.

 

[tomhaney1]

Thanks for your time, could you possibly tell me how to do that? like a walk through preferably.



I havent even thought to disconnect the battery. and i dont have any intake or airbox mods, unless the previous owner did them, but i highly doubt that. he used the rig only to tackle the concrete jungle of his sons daycare. my rig is (to my knowledge) as stock as it gets.

Thanks guys, this site is really helpful, and i really do appreciate the responses and advice.

You might want to have a mechanic clean it if you are unsure. It is possible to ruin the sensor. I don't want that on my hands. I am also not so familiar with that generation to give you a walk-through of the process. Any mechanic should know how to clean the sensor though.

 

[4reak]

You might want to have a mechanic clean it if you are unsure. It is possible to ruin the sensor. I don't want that on my hands. I am also not so familiar with that generation to give you a walk-through of the process. Any mechanic should know how to clean the sensor though.

ok, sounds good. my older brother for some reason thinks he can do all the car stuff, so i was mainly asking on here to throw some ideas his way. but if it were up to me, mechanic here i come! hahaha. thanks for the response.

 

[tomhaney1]

ok, sounds good. my older brother for some reason thinks he can do all the car stuff, so i was mainly asking on here to throw some ideas his way. but if it were up to me, mechanic here i come! hahaha. thanks for the response.

No worries. I would clean the sensor and then also check the sensor to see if it is bad. Then move from that point back. But also see what the code says. Don't trust someone telling you that the code is "no big deal". One small issue can cost you an entire emissions system.

 

[gapboi210]

never take advice from Autozone.... and avoid their parts if possible.

 

[Greedy]

Cleaning the MAF is very easy, just be careful with it. It is located near your air box on the intake tube before the resonator (big plastic box between the air box and throttle body). The MAF has a square plastic top with two screws on opposite corners holding it in place. It is connected to 5 wires in a loom via a clip. All you have to do is the following:

1. Remove the wires by un-plugging the clip.
2. Remove the two screws holding the sensor in place - be sure not to strip the screws as they hold pretty tight.
3. Carefully pull the MAF out - note that it has a long protruding portion that holds the delicate wires that make the sensor work.
4. Look at the sensor - there are two wires, one you can see near the end, the other is inside the protruding portion up near the square top.
5. Use electronics part cleaner (I got mine at radio shack) to spray the bottom wire and also up into the tube where the other wire is - don't worry about the cleaner damaging anything if it pools up in the tube, it is sealed. Use liberal amounts of cleaner.
6. Turn the sensor over to drain the cleaner out of the tube.
7. Set the sensor on it's side on a paper towel somewhere it will not get knocked off a table or stepped on and allow to dry for an hour or so.
8. Reinstallation is just the opposite of removal.

Let us know if you still get the code and we can try something else!

Gregg

 

[RunnerUp]

a p0171 is a dirty maf, clean it as good as you can, then reset your system or go back to autozone and have them clear the code

 

[Dreamw0rkz]

i am a mechanic , got my own shop it Long beach , but yeah .. go buy a can of electronic parts cleaner , kinda like a brake cleaner or carb. cleaner , , take out your Mass Airflow Sensor thats connected on your air intake pipe , near the air filter and carefully spray it inside the end part and make sure your holding the can kinda far away from the sensor because the spray can has pressure enough to damage the sensor wire thats inside the long tube like .. spray it clean and wipe the ball like sensor with a Q tip and let it dry before putting it back on or reconnecting .. you can disconnect the battery to delete the check engine light but if that doesn't work disconnect both cable on the battery and touch each other to drain watevers left in the system.. make sure its not connect to any battery !!!!! hope that helps..