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Category: Ford
Satisfied Customers: 26457
Experience:  ASE CERTIFIED TECHNICIAN ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
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2002 Explorer Sport Trac: check engine..p0171..maf sensor, but light

Resolved Question:

2002 Explorer Sport Trac - "check engine" light has been are p0171, 0174, 1131, & 1151. Have replaced maf sensor, but light keeps coming on. Any thoughts?
Submitted: 7 years ago.
Category: Ford
Expert:  AMEDEE replied 7 years ago.



These codes are lean codes. A lot of the times it is just a bad mass air flow sensor causing these codes. It is always a good idea to clean the keep alive memory in the computer when replacing the mass air flow sensor otherwise these codes may come back. This may be your entire problem. The only other thing would be a big fat vacuum or air leak. Check along the intake manifold gaskets and vacuum hoses and lines ot be sure that none of them are leaking. ALso, check the air snorkel after the mass air flow sensor for cracks and ripes.

Customer: replied 7 years ago.

Hi, I've replaced the mass air flow sensor and had the computer reset. I've also checked for intake gasket leaks. Vacuum hoses all seem fine. Any other thoughts?



Expert:  AMEDEE replied 7 years ago.
YES.... its going to be one of those two things. You need to get your intake smoked check for air/vacuum leaks. If there are none, then you could have a defective mass air slow sensor. You can view the mass air flow sensor readings on a scan tool that can read live data.
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