Codes are:

  • P0101 mass air flow circuit failure.

  • P01071 bank 1 lean and P0174 bank 2 lean.

Did a replacement of the intake manifold gaskets and a fuel injector de-carbonization service. After 40 miles of driving the check engine light came back on.

Any suggestions to what may be wrong? EGR valve?

  • try cleaning the mass air flow sensor.
    – user4546
    Commented Apr 28, 2015 at 22:54

1 Answer 1


When you reset the lights, it takes a few miles (and certain conditions) for it to get back to a ready state. When it gets there, if it isn't fixed, the lights will pop again. I'm wondering if you have a leak in your intake tract somewhere. Seems you were thinking that way when you replaced the intake gaskets. I'd look at the intake tube between your MAF and the throttle body. Also, look at any of the vacuum lines which attach to the intake. Double check all of the bolts on the intake (but don't over tighten). There are plenty of places air could be leaking in.

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