2000 Toyota Corolla P0171 code

2000 TOYOTA COROLLA
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JJJDSN
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  • 1 POST
2000 Toyota Corolla 4 cyl 200000 miles

I have a 2000 Toyota Corolla with P0171 code. At first, I cleaned MAF sensor with a cleaner and cleared the code, but the code came back on the next day. The second time, I thoroughly cleaned (Only Spraying the cleaner more thoroughly) MAF sensor again and replaced the Air Filter, but the code came back again. It seems that the code only appears when I drive local (less than 45mph) for about an hour or so because the code never came on when I was driving on the freeway.
Feb 3, 2010 at 6:53 PM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,992 POSTS
P0171/P0174 Lean A/F mix:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)
Feb 3, 2010 at 7:13 PM
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CHANDRAP
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  • 5 POSTS
I do have the same problem... I am getting when driving slow but not on highways. This is all coming after I changed my airfilter bought at Kragen (cheap one for 7/-) and I did vacuumed the airfilter enclosure... I even scratched the material that stick to it, while vacumming, is that has any effect I don't knoiw...

Please help me to get t\rid of this problem... I have to commute 60 miles each way everyday on it...

Some say cleanin og MAF? where can I find the MAF on my 2001 TOYT Corolla CE?

Thanks so much...
Feb 9, 2010 at 5:49 PM
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