How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jay Your Own Question
Jay, Certified Infiniti Technician
Category: Infiniti
Satisfied Customers: 3818
Experience:  20+years, Nissan and Infiniti experience and currently now working for a Infiniti Dealer
Type Your Infiniti Question Here...
Jay is online now
A new question is answered every 9 seconds

Very poor fuel economy (9.5 miles to gallon). Codes P0171,

Customer Question

Very poor fuel economy (9.5 miles to gallon). Codes P0171, P0171P & P0507. 2008 G35X
JA: Has the vehicle turned into a gas hog? And how does it start -- same as usual?
Customer: Yes, Gas hog but always starts right up.
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: Cleaned 2 MAF sensors & changed vapor canister vent valve.
JA: Anything else you think the mechanic should know?
Customer: no
Submitted: 11 months ago.
Category: Infiniti
Customer: replied 11 months ago.
I also need to know rough estimate. To see if it's worth fixing.
Expert:  Jay replied 11 months ago.

Hello my name is ***** ***** thank you for your question.

Do you have cold air intakes or K&N air filters on this car?

Customer: replied 11 months ago.
Expert:  Jay replied 11 months ago.

Is the car completely stock? Did you clean the throttle chambers also?