2002 Ford F-150 Diagnostic Codes 171/174

Tiny
MIKE KNOX
  • MEMBER
  • 2002 FORD F-150
Engine Performance problem
2002 Ford F150 Two Wheel Drive Automatic 92000 miles

I have rec'd these codes. Both indicate system too lean. What can be the cause and can I repair myself?
Monday, March 31st, 2008 AT 6:24 PM

1 Reply

Tiny
SERVICE WRITER
  • MECHANIC
  • 9,123 POSTS
I have seen dirty MAF sensors cause this combination.

ALthough an air leak after the MAF such as an intake plenum gasket leak can cause this as well.

Try cleaning the MAF with electrical cleaner and let it dry. You can spray some carb cleaner around the intake and watch for an idle change.

IF nothing simple like this helps we can go into testing.
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Monday, March 31st, 2008 AT 6:36 PM

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