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mike, BMW Technician
Category: BMW
Satisfied Customers: 1162
Experience:  bmw master tech ase certified
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What could be causing p0171 and p0174 on a 525i BMW 2001?

Resolved Question:

what could be causing p0171 and p0174 on a 525i BMW 2001?
Submitted: 5 years ago.
Category: BMW
Expert:  mike replied 5 years ago.

mike :

Hi fuel trim bank 1 and bank 2 faults. It could be a mass air flow sensor you need a scan tool that can read the readings it is giving. A little more common is the air intake boot torn. Follow the tubes from the air box to the throttle body The last boot at the throttle body is the one that is normally torn look all around it even the bottom half of it very common. Thanks mike


I will check that out and get back to you

mike :

ok let me know

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