2006 5.4l expedition engine serioously lacks power codes p0171 and p0175
p0171 and p0175
bank 1 too lean and bank 2 too rich
these codes dont make sence to me, this vehicle has a commonrail fuel system and a connected intake.
the engine lacks power so much so that it is undrivable. it hesitates and stumbles, it has yet to stall but acts like it wants to.
I have checked the maf and it is working properly.
I have removed both cats and saw no change.
I have tested vacuum and am seeing 15hg steady.
I have pressure tested the cooling system and am losing no coolant.
I have seen no smoke with the cats removed so I am doubtful of bad rings or head gaskets.
The engine idles steady, it almost feels like a terrible misfire but the lack of misfire codes leads me to think otherwise.
It will routinely act as if I am not applying throttle when I am.
I need to know how much vacuum this engine should generate at idle,
what numbers should a working tps read?
How dangerous is spark plug removal on this engine?
Any thoughts suggestions or ideas?
Beins this is a 3 valve engine, spark removal can be a pain, but i can give u some tricks that will help if u r interested. Is p0171 and 175 the only codes? I dont believe i have ever seen this problem. a rich and lean code set at the same time for the same bank. that is odd...i wouldnt think it would be fuel supply related beins its on 1 bank instead of both. But i could see fuel delivery to cause this issue. I have seen alot of trouble with injectors in this engine, but u normally have a missfire code such as p03xx depending on which cylinder is missing. I would recommend pulling the fuel rail up out of the intake. Leave the fuel lines connected to the rail and have some one turn the key on while u watch the injectors. There should not be any fuel to come out of the injectors with KOEO. If an injector does leak fuel replace it....
I have seen the electronic throttle bodies due some weird things as well, but they normally set dtc's as well/
I would also recommend watching the o2's and see what they r doing. R they running rich and then lean on bank1? What is really happening? U could have a PCM issue as well... Hope this helps
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