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john -aka eauto
john -aka eauto, The Car Guy
Category: Ford
Satisfied Customers: 15038
Experience:  ase tech over 15 years in the field
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get error codes p0300 & p0174

Customer Question

get error codes p0300 & p0174
Submitted: 7 years ago.
Category: Ford
Expert:  john -aka eauto replied 7 years ago.
HiCustomer Thank you for asking your question on JustAnswer. The other Experts and I are working on your answer. By the way, it would help us to know:
-What year is your Ford?
-What model is your Ford?
-How many miles are on your Ford?
-What type of engine is in your Ford?
-What have you already tried?

Thank you again for trusting us with your problem. Please reply as soon as possible so that we can finish answering your question.
Customer: replied 7 years ago.
mileage is 260,000
Customer: replied 7 years ago.
Happens only when it is cold outside. When it is warm it does not happen.
Expert:  john -aka eauto replied 7 years ago.

po300 code random multile cylinder misfire * start with a tune up

po 174 is a lean code this is a little more complex

P0174 or PO171 OBD-II Trouble Code

Technical Description

System Too Lean (Bank 1)

What does that mean?

Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1.

Note: This DTC is very similar to P0174, and in fact your vehicle may show both codes at the same time.


You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.


A code P0171 or 174 may mean that one or more of the following has happened:

  • The MAF (Mass Air Flow) Sensor is dirty or faultyNote: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
  • There could be a vacuum leak downstream of the MAF sensor.
  • Possible Solutions

    Possible solutions include:

    • In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
    • Inspect all vacuum and PCV hoses, replace if necessary
    • Check for a dirty fuel filter and proper fuel pressure