Novice mechanic and first time poster. Need some help diagnosing why my 2004 Ford Expedition is running way too rich. I have the 5.4L triton with 180K miles (4x4 eddie bauer) and recently just changed the intake manifold (collant leak at cross over), fuel injectors, new plugs, new PCV hose connector (has heated sensor), new spark plug boots, new MAF, new oxygen sensors (2 upstream and 2 downstream) and new vacuum hoses. Im still getting P0172 (system too rich bank 1), P2196 O2 sensor stuck, rich bank 1 sensor 1 and P2198 O2 sensor signal stuck, rich bank 2 sensor 1. As a result I'm burning twice as much fuel and I'm not sure what else i can do. I hooked up my scanner and im getting the following data (which i believe confirms too much fuel - see trim data below):

-Fuel Sys 1 CL
-Fuel Sys 2 NA
-Calc Load (%) 23.9
-ECT (*F) 201
-STFT B1 (%) -17.2
-LTFT B1 (%) -25.0
-STFT B2 (%) -14.1
-LTFT B2 (%) -25.0
-Spark Adv * 20.5
-IAT (*F) 88
-MAF (lb/min) 0.8
-TPS (%) 18.8
-O2S B1 S1 (V) 0.470
-STFTB1 S1 (%) -17.2
-O2S B1 S2 (V) 0.755
-STFT B1 S2 (%) 99.2
-O2S B3 S1 (V) 0.195
-STFT B3 S1 (%) -14.1
-O2S B3 S2 (V) 0.720
-STFT B3 S2 (%) 99.2

Being a shade tree mechanic my instinct is to keep replacing sensors, but they cost too much. Could the canister purge valve solenoid or EGR valve pressure sensor cause too much fuel? Any help is greatly appreciated. Cheers and thanks in advance for dropping knowledge on me!

 

Since both banks seem to be almost identically rich, the source of your issue is going to be something that is common to both banks. (Are you getting the P0175?)

That '04 5.4L 2-valver should have a returnless fuel system, so the fuel pressure regulator is in the fuel tank. The PCM will be controling the fuel pressure.

Before I'd change any sensors, I'd like to confirm that the fuel pressure is with in spec. Get a fuel pressure gauge on it and check the fuel pressure with KOEO and again with KOER. You're looking for ~55 psi in both condictions.

 

Double check the PCV elbow at the rear of the intake. You're readings lead me to believe that you have a large vacuum leak.

 

I can see from your readings You have a Malfunctioning Mass Airflow Sensor, Assuming these readings were taken at Idle you should be showing min 6 to 8 lb/min of MAF and u show 0.8, Since your Computer thinks the airflow is so low, It is trying to trim fuel, If your MAF reading is correct then you have a plugged air filter, which would definately cause a rich condition.