codes P0171,P0174
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Joined: Dec 2002
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From: fl
codes P0171,P0174
I just changed oil and cleaned K&N filter, I have 99 f-150 with 59,000, changed fuel filter last oil change, so I cleaned Maf and still getting codes, should i be looking for a vac leak, also changed pcv last oil change, had same codes 3,000 miles ago, all has been good till know , any help? thanks
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Joined: Jun 2002
Posts: 10,511
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From: Under the flightpath of old ORD 22R
With both banks showing lean, check that the K&N is not over oiled, and coating the MAFS wire.
How did you clean the MAFS ?
When you put it all back together, did you check all the lines to the intake elbow to make sure none are pulled part way out ?
Is the IAT sensor installed completly ?
It is easy to put it together and have one look like it is on, but it is letting in un-mettered air, cposs causing the lean condition.
The main ones as of late seems to be either clean the MAFS or the cracked elbow on the back of the T/B for the PCV.
This is why I asked how the MAFS was cleaned, and to make sure you don't have an over oiled filter installed.
If the MAFS is still clean ( and the filter is not over oiled ) next is to check the PCV elbow on the back of the T/B for cracks. When you go to get this part it is a new elbow, tube and PCV as a kit.
There are other things, but these seem to be the first ones to check on. doing a search on P0171 will show 36 threads with some of the results posted back from other members.
Post back with some results.
Good luck
How did you clean the MAFS ?
When you put it all back together, did you check all the lines to the intake elbow to make sure none are pulled part way out ?
Is the IAT sensor installed completly ?
It is easy to put it together and have one look like it is on, but it is letting in un-mettered air, cposs causing the lean condition.
The main ones as of late seems to be either clean the MAFS or the cracked elbow on the back of the T/B for the PCV.
This is why I asked how the MAFS was cleaned, and to make sure you don't have an over oiled filter installed.
If the MAFS is still clean ( and the filter is not over oiled ) next is to check the PCV elbow on the back of the T/B for cracks. When you go to get this part it is a new elbow, tube and PCV as a kit.
There are other things, but these seem to be the first ones to check on. doing a search on P0171 will show 36 threads with some of the results posted back from other members.
Post back with some results.
Good luck
Thread Starter
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Member
Joined: Dec 2002
Posts: 12
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From: fl
I clean the maf buy spraying some electrical cleaner on the wires, i do not take maf out just undue filter housing and spray, I do not think filter is over oiled only spray small amount, as had that problem before, i lookded at my pcv vac line and it seems to be all one piece to back of tb no elbow?? thank for the info
