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internal88
internal88, Technician
Category: Hyundai
Satisfied Customers: 2541
Experience:  Over 10 years in the Import Auto industry. Engineering background and diagnostic is my specialty.
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I have a 2005 hyundai sonata 2.7l. hayve PO171 and PO174

Customer Question

I have a 2005 hyundai sonata 2.7l. hayve PO171 and PO174 codes. only thing that i have noticed is a drop in fel milage from 27mpg to about 24mpg. what might the be the problem.
Submitted: 1 year ago.
Category: Hyundai
Expert:  internal88 replied 1 year ago.

Hello, I'm Brandon - Hyundai tech.

This is an air flow issue.

Expert:  internal88 replied 1 year ago.

80% of time it is a bad mass air flow sensor that trigger this code. It is making the fuel trim goes lean.

Expert:  internal88 replied 1 year ago.

15% of time is the air tube is cracked or loose. Inspect for any loose clamp or air leak.

Expert:  internal88 replied 1 year ago.

5% is the bank 1 sensor 1 oxygen sensor fault.

Expert:  internal88 replied 1 year ago.

All of these sensor cause the fuel consumption to go up.

Please rate me positive for the prompt service, thank you.