Help! Code P0171...
 

I have a check engine code that reads P0171....fuel system too lean. My car is a 2000 Sonata and I have just recently had the oil changed, fuel filter/ injectors /system cleaned and the transmission flushed. The code was on before I had any work done.
I did try to research it a little bit online and found that some are saying it's the mass air flow(MAF) sensor and it might need to be cleaned?!
Any ideas on what I should do OR where this darn thing is located!! I dont know where to look!
Any help is VERY MUCH APPRECIATED!!!

The car kills on me about 4-5 times on the first start up of the day and idols rough. Once I finally get it going and out on the road she does pretty good but still idols crappy! :(

Thanks in advance!!
Em

If it was a snake, it would bite you. I assume you have a 2.4 L I4 motor. See diagram.

To clean it, remove it from the rubber intake, and spray down with MAF cleaner, or some sort of electrical automotive cleaner. Don't use carb cleaner, the element in the MAF is very delicate. Don't touch it with your finger, etc. You'll break it, and a new MAF is $200+.

If that doesn't help, look for an intake leak after the MAF, or consider changing the fuel filter or doing a fuel pressure test.

Thank you!! I will hopefully give it a shot....right now that part would run me around $450-$500 :-(
Can you tell me where I can find diagrams like the one posted?

(I did have the fuel filter replaced a few weeks ago.)

Thnak you!

Oh and now I have a new code ...they didnt give me the number...but it says fuel control circuit - low input.
Anyone had this before?

Need that code. You find the diagrams at hmaservice.com.

I have the same problem. Have you solved it yet?

We have fixed my problem!! I bought a can of CRC Mass Air Flow Cleaner for 6.99 at one of our local auto stores and low and behold my car runs normal again! I was so flippin' happy!! After many technicians looking for problems it was that simple!

Thanks SO much to jsinton for posting that diagram my fiance found it right away!:)

In my research I have found that any code from P0171 to P0175 has to do with the MAF sensor, so if you have any of these codes I would first suggest to clean your MAF sensor. Be very careful as they are delicate and about $200 to replace.

I am having the same problem. I replaced the MAF sensor but it still shows the same problem. I hooked up my scanner again and I still see no voltage movement for the MAF sensor.

I believe I have a wiring problem.

Any help with this is appreciated,

Paul

Look at the short PCV hose for collapse/split-vacuum leak adjacent to the nipple at the intake plenum..