2005 F150 P0171 and P0174 codes
double_ought2
05-03-2016, 05:23 PM
Just changed all the plugs in my 2005 F150 4x4. Now throwing these lean codes. Checked all the vacuum lines, replaced the fuel filter, and cleaned the MAF sensor. Idling and running bad . Was running fairly good before the plug change except for an occasional stutter at accelaration at road speed.
would apppreciate any suggestions.
would apppreciate any suggestions.
65comet
05-04-2016, 09:49 AM
In a Ford the most common cause is dirty MAF sensor. Since you cleaned it, maybe it is going bad. Search youtube for videos on how to test a MAF sensor.
Next is vacuum leak from PCV line or intake. The PCV line has a foam insulator over most of its length and I've seen a couple snap in half mid way but aren't visible.
Intake leak can be found out as an example in this video water testing in the last half of it, skip past the first half if you don't have a scanner.
https://www.youtube.com/watch?v=K-on2hbYUCc
Next is problems with the EGR. You changed the plugs, but the COP's may have gone bad for multiple cylinders. These are just a few of the things that can end up pulling those codes. The fuel pump could be going out with intermittent loses or the fuel pump driver module might have corroded out the back side.
Next is vacuum leak from PCV line or intake. The PCV line has a foam insulator over most of its length and I've seen a couple snap in half mid way but aren't visible.
Intake leak can be found out as an example in this video water testing in the last half of it, skip past the first half if you don't have a scanner.
https://www.youtube.com/watch?v=K-on2hbYUCc
Next is problems with the EGR. You changed the plugs, but the COP's may have gone bad for multiple cylinders. These are just a few of the things that can end up pulling those codes. The fuel pump could be going out with intermittent loses or the fuel pump driver module might have corroded out the back side.
double_ought2
05-04-2016, 11:12 AM
Thanks. I've already ordered a new MAF sensor and will try that next. Do you think the COP's would have gotten bad after changing the plugs? I have one new one and tried it in the bank 2 side one at a time. Made no difference, but it wouldn't if more than one is bad.
Well if the MAF sensor doesn't fix it I'll try a fuel pressure check next. Thanks for your reply 65comet.
Well if the MAF sensor doesn't fix it I'll try a fuel pressure check next. Thanks for your reply 65comet.
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