Hey all , i have been searching all week and cant fine the direct answer to my issues , so i decided to make a thread and see what i can fine out from my fellow forumer . So i have a 2006 Lincoln Navigator 5.4L 3V With about 55508 miles on it . for about a week and half i notice on startup the truck sounded a little different , until the different went to not normal at all . On startup the truck would crank crank crank , nothing then crank crank crank again and it'll will start or it would crank and start immediately. so i put my scanner on it and it came up with PO172 system too RICH (bank1) so at that point i go into Live Data , and go down to the O2 sensor and got at idle LT 15 to 30 or more sometimes , ST -3 to 12 , LT3 to 9 , ST -2 to 6 . So for some reason this truck is dumping fuel and i cant figure it out , i checked around for vacuum leaks , is there anything to check for under the truck ? all help is appreciate . and again i searched and couldnt fine anything related close to what problems im having .

 

are you talking about long term and short term fuel trims? cause if you are im confused you have alot of differnt numbers there that dont seem to make sence...can your scan tool see freeze frame data? that would help out alot.

if your truck is setting a system rich DTC i can tell you it will not be a vacuum leak, that will set a lean DTC P0171 or P0174. Is there any other DTCs? Keep in mind generic scan tools sometimes will not display manufacturer specific DTCs.

A stuck open injector is a possibility as well, if it feels like its missfiring at all DO NOT drive it.

 

Yes im refering to long term / short term . the numbers i put up is what its fluxuating between . i will check tomorrow for the freeze frame data , and yes the idle is rough as if its misfiring . thanx for you help

 

thanx for your help , i set an appointment up for monday morning to drop the truck off at the dealership . And it will be towed in .

 

good decision, post back their findings!