That O2 is before the Cat. You should also check your HEGO fuse, under the hood.
The DPFE is usually on the intake, but yours appears to be by the intake rubber tube near the throttle body. It is usually mounted with two 8mm bolts.
Don't mix up the two DPFE hoses. Inspect the two hoses and the metal tubes they attach to for holes/cracks. The hoses are special silicone high temp, NOT normal AP store vaccum hose. Get them at Ford if they are bad.
Reset the computer after replacing the DPFE and O2 sensor.
Let it idle 5 min in P then 5 min in D, then drive normally. This step is not crucial but will help it re-learn a good idle. Add 5 min in P and D with the AC on if equipped.
Neither of these problems is a dire emergency. Your gas mileage will suffer, that's about it. Might not run good at light throttle steady speeds.
The O2 sensor is the harder of the two parts to change. I'd guess 20 minutes tops if you need the special socket.
The DPFE couldn't take 10 minutes if you took a beer break 1/2 way through.
2000 2.5 MO5D 4.10 one-wheel drive DD - gave to my older son
1990 STX 87 2.9 going in.....Junked it
2000 3.0 4WD M05D 4.10 S-cab Off-Road package with 235-75-15" tires, hotrod DD, lol
Last edited by Earl43P; 04-13-2011 at 12:49 PM.