Codes P0171 and P0174

Tiny
JACARRA
  • MEMBER
  • 2000 MERCURY SABLE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 109,190 MILES
Whenever the car is idle, it begins to jerk and every now and then it will cut off, but I can immediatlely restart the car. When I am driving (accleraitng) the car runs fine. I took the car to get diagnosed and I was given codes P0171 and P0174. It was explained to me that the computer has recognized a rich or lean condition on one engine bank only and the probable causes are : If bank one and two codes set together then it could be the MAF sensor or fuel pressure, 2, Oxygen sensor defective, 3, Ignition misfire-repair or 4, Fuel injector problem. I read that I may just need to have my MAF sensor cleaned. What do you think it could be?
Wednesday, January 21st, 2009 AT 1:11 PM

5 Replies

Tiny
ZACKMAN
  • MECHANIC
  • 4,202 POSTS
When both banks are lean, it has sth to do with your MAF sensor. Try cleaning it.
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Thursday, January 22nd, 2009 AT 2:38 AM
Tiny
JACARRA
  • MEMBER
  • 2 POSTS
Thank you for that. I did read many forums, but wanted to be sure before taking it in to Ford and spending hundreds of dollars. The problem was a hose had collapsed. So I had a pcv valve replaced, the hose replaced and just to be sure, the MAF cleaned with celectronic cleaner.
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Thursday, January 22nd, 2009 AT 7:48 PM
Tiny
ZACKMAN
  • MECHANIC
  • 4,202 POSTS
I mam glad your problem is fixed. Come back anytime.
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Thursday, January 22nd, 2009 AT 9:39 PM
Tiny
MILO066
  • MEMBER
  • 2 POSTS
I went through this recently. The vent tubes from the cam covers to the air intake downstream from the MAF were broken. Specifically the angle adaptors that interface the plastic tubes to the cam cover, rubberish devices, had rotted out underneath the "knee". This let air get in.
Dorman 46027 PCV Valve Elbow for Select Ford/Mercury Models
from Amazon for $10 fixed it.
You can reach the one on the rear cover from the passenger side using your left hand/arm.
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Friday, August 27th, 2021 AT 6:36 AM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
Hello,
That is a very good piece of information. Appreciate you sharing it with us.

Thank you.

https://www.2carpros.com/articles/mass-air-flow-service

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Friday, August 27th, 2021 AT 4:51 PM

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