How do I replace ball joints.
 

98 Expedition 5.4 started squeeking about a month ago. Must be the ball joints. It squeeks just sitting still turning the steering wheel. Hopefully it's just the lower ones. Anyone know the procedure to remove the ball joints. It's been many years since I did a ball joint job. Looks like I can set the lower A frame on a jock, remove the tire, remove the ball joint nut, drive a ball joint fork between the A frame and ball joint stem and out she comes. I hope. Is the ball joint welded to the A frame? Any advice would be appreciated. Thanks, Dennis

PS almost forgot, the air compressor for the air ride has started comming on an off frequently. I suppose I now have an air leak somewhere. The more complecated these cars get the more they break down.

A little background
Unfortunately I have 98 Ford Expedition, 5.4 Automatic 4x4.
The car will barely run at idle. It usually dies. Driving is ok. At a stop I have to keep it at about 1000 RPM to keep it from stalling.
The code scanner says P0171 bank 1 is running lean, P0174 bank 2 is running lean Knowing that the fuel system is running lean is just about useless information when the cause could be a dozen different things. What good is a senser if it can't tell you what part needs to be replaced? I'd like to take all these useless sensors and stick them where the sun don't shine on the idiot that designed them. I guess Ford just likes to piss off their customers so we will buy from Chevy next time. Well they have convinced me. Unfotunately Chevy is probably just as bad.

I have replaced:

Air Filter
Fuel Filter
Fuel Pressure Regulator Valve
No improvement, Same codes.
Replaced: Two O2 sensers on the engine side of the catolitic converter.
Idle Air Bypass Valve.
No improvement, In addition to the P0171 and P0174 codes I know have:
P1131 Insuff. Switching O2 Bank 1 Sensor Sensor/Lean
P1151 HO2S Bank 2 Sen 1 Insuff. Switching Lean Mean.
Replaced:
Mass Air Flow Senser
EGR Valve
While installing the EGR Valve I broke what appears to be a vaccuum nipple on a component located on the fire wall above and to the left of the power brake vaccuum booster canister. The vaccuum line attaches to the bottom of the componet and comes from the same harness for the the vaccuum line to the EGR Valve. It may be the Vapor Pressure Scensor. There is a short tube coming from the top right with a tage that reads "EVAP service port and something about using only regulated pressure". It has two large vaccuum line coming from it and a two wire electrical connector

I just replaced the lifters on the driver bank. Found an air leak where the EGR valve was not tightened down enough. Disconnected the battery to reset the computer and hallalua the service engine light finally went out. Two days later it came back. With the exhaust manafold stud lower rear driver side twisted of by previous owner or mechanic, I can't tell it the noise is the exhaust leak or still a lifter. After I get the stud out and replace the manafold gasket maybe the noise will be gone. Now on to the ball joints.

RE: How to replace lower ball joints.
 

Sounds like you have done quite a bit to this engine. Ball joints are a pretty large task on this vehicle. You will need a ball joint press and have to disassemble the entire hub to remove ball joints.. Also please don't blame mechanic or previous owner for the condition of ex manifold studs they break on their own all the time, just look at the condition of the rest of them. I'm sure replacing that gasket will be fun for you. IMO u should just torch off the nuts to leave yourself enough stud at head to extract once manifold is off.