What causes lean codes?
06-09-2011, 05:38 PM
#13
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sometimes lean codes can be caused by low fuel pressure....if you have dual tanks on your truck check fuel pressure in both tanks.......
if engine light comes on switch to rear tank ,unplug the neg battery cable for few minutes to reset computer run the truck for a few days if light remains off then u got a bad fuel pump in front tank..try it in reverse if liight comes on u know it is the pump..
if not check make sure u dotn have bad plug wires or a bad plug....best way to check the wires is at night...a damp night preferably...if u see sparks under the hood when engine is running hehe u got badwires....
other than that i am not sure of what else would cause it...
if engine light comes on switch to rear tank ,unplug the neg battery cable for few minutes to reset computer run the truck for a few days if light remains off then u got a bad fuel pump in front tank..try it in reverse if liight comes on u know it is the pump..
if not check make sure u dotn have bad plug wires or a bad plug....best way to check the wires is at night...a damp night preferably...if u see sparks under the hood when engine is running hehe u got badwires....
other than that i am not sure of what else would cause it...
. dont worry, your not in the water so you wont get zapped!
02-07-2018, 11:28 PM
#14
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I had fuel contamination, crap in the rails and injectors, might want to see my post in "Another P0171/P0174 question". Fuel filter was really dirty, recommend fuel system cleanout. Change filter every 30k they say. Mine f150 has just 69k on it...
Last edited by 150fromhell; 02-07-2018 at 11:32 PM. Reason: info
02-09-2018, 08:56 AM
#15
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I would think a no spark event in any particular cylinder would cause a lean spike from the O2 sensor's point of view.