Expedition & Navigator1997 - 2002 and 2003 - 2006 Ford Expedition and Lincoln Navigator
Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.
You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!
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
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.