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Q: i have a check engine light on

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i took my car to get the check engine checked and they gave me codes p0012 and p0171. i took my car to my mechanic because i recently got my engine fixed and i took it to fix the air leak. but now idk about the camshaft if i need to replace it or something else

My car has 121000 miles.
My car has an automatic transmission.

Hello there, thank you for asking about your 2004 Toyota Camry. Code P0012 relates to the camshaft position sensor which monitors the speed of the camshaft and relays this information to your car’s computer, which helps to control ignition timing and fuel injection pulse. Code P0171 relates to a lean air/fuel mixture which can be caused by a number of things such as:

  • Intake air leaks
  • Faulty front heated oxygen sensor
  • Ignition misfiring
  • Faulty fuel injectors
  • Exhaust gas leaks
  • Incorrect fuel pressure
  • Lack of fuel
  • Faulty Mass Air Flow (MAF) sensor
  • Incorrect Positive Crankcase Ventilation (PCV) hose connection

I would recommend having an expert from YourMechanic come to your home to diagnose your codes](https://www.yourmechanic.com/services/check-engine-light-is-on-inspection) and replace the camshaft position sensor if needed.

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