Codes P0171 and P0174?

2007 NISSAN MAXIMA
240,000 MILES • 3.5L • 6 CYL • 2WD • AUTOMATIC
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DUWHOP31
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My car is showing codes P0300 random misfire P0171 and P0174 (fuel trim Bank 1 and Bank 2 mixture too lean) i know what the P0300 code is (either a spark plug, or one of the engine coils, but i don't know or understand what the P0171 and P0174 are.
Jul 29, 2022 at 9:44 AM
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SQM
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Hello,

Those system lean codes get triggered when the air fuel ratio becomes too lean. Which means the optimum air / fuel ratio has not met. Which can be due to a number of components. It could be for leak in the air intake, faulty fuel injector, exhaust leak, incorrect fuel pressure, bad mass air flow sensor etc.

I have attached the complete trouble shooting guide for the codes P0171 and P0174 below. Follow those steps as it can help you determine what the issue is.

Let me know of any questions.
Thank you.
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Jul 29, 2022 at 4:00 PM