I just bought a 99 expedition 5.4l has 253k on it but the other owner said it had a motor put in at 203k. It has a miss in the engine and I have several codes and will try to post them in just a few to see if anyone can help diagnose this for me. I will also try to post pics of it as well.

 

p0171
00174
p0455
p0152
p0401

any help on these issues would be much appreciated.

 

p0171 - System Too Lean (Bank 1)

p0174 - System Too Lean (Bank 2)

p0455 - Evap Emission Control System Leak Detected (Gross Leak/No Flow)

p0152 - Heated O2 Sensor Circuit High Voltage (Bank 2, Sensor 1)

p0401 - EGR Flow Insufficient Detected




when is the last time anyone did any maintainence to your expy?

ie: change the cops, plugs, clean the TB, fuel injectors, MAF, change the 02 sensors, and check the egr system for leaks/clogs?

 

I didn't ignore this thread, just didn't get back to it. Thanks for the details on the codes.

I do not know the previous owners service details. I know that one cop has been replaced as it is not a motorcraft like the others. Other than that the previous owner says the motor was replaced about 50k ago and the trans was just very recently replaced but didn't give me a date or anything.

 

sounds like you need a complete tune-up as described above


have you done an oil change yet since the purchase?

 

I haven't done that yet, but did check all fluids and the oil is filled to max and looks, feels and smells normal, not burn color or smell.

I will throw a filter and some fresh oil in it soon though as I do not know how long it has been in there.