Rocko1

05 F150 with the 5.4 has lost a ton of power and just runs horrible. Pulled the codes and wow, this is what came up.

PO171 Sys too lean Bank 1
PO174 " " Bank 2
PO175 " " Rich Bank 2
PO300 Random Misfire
PO303, 304, 305, 306, 307
PO316 Misfire occurred in the first 1000RPM's
PO430 Bank 2 Catalyst Efficiency below limit.

Cam Sensor
Crank Sensor
Full pump pressure

Where to start? Compression test? Help, thanks.

Mod (Ret.)

Check the fuel pump control module, as it can cause all of these, and it's also listed as "Fuel Pump Pressure"

Located by the spare tire. Drop the spare tire, then look at the chassis rail that runs from the left to the right side rails (this chassis rail would be where the front of the spare tire is if it is in it's raised position). There will be a module about 7 to 8 inches by 3 inches, and is mounted with two bolts to this chassis rail. It is common for it to corrode on it's backside, the side that is against the rail. It controls the "on/off" of the fuel pump located in the gas tank. Since Ford does not use a "return line" from the fuel rails that feed the injectors, the fuel pressure is controlled by this module turning on/off the fuel pump, based on the pressure that is read by a sensor in the fuel rails.

I'd check this first. If it's backside is corroded, it is most likely bad, and your fuel pressure is off, and causing all these lean and misfire conditions. Strange though that one bank is rich, and the other lean.

Don't go out and buy one yet until you look at its condition. They are expensive (around $150.00). I don't like to have folks throw parts at a fault in attempts to correct it.

Rocko1

I will give it a look. Thanks.

Would this also be referred to as the fuel pump 'drive' module?

Mod (Ret.)

It's free to inspect it. If it's not corroded, then it may not be your fault. The lean bank for one side, and rich bank on the other has me scratching my head, but the "fuel pump pressure" and lack of power lead me to fuel delivery problems.

Again, check it and see if it's corroded. Some are even rotted through on the backside, a sure indication that the electronic module inside has moisture. Electronic circuit boards don't fair very well with that.

This part was recommended to a poster on another thread, but he had different symptoms; black smoke initially, indicating a rich mixture which ended up being a stuck (open) injector. Then he experienced white'ish smoke, which ended up being oil, as he had a bent rod from the raw fuel getting into the cylinder and being compressed (much like what water would do), pushing against an open valve, and hence, the bent pushrod.

techrep

iTrader: (1)

If that ain't it try checking your Cat's

Rocko1

We are inspecting it now. My gut tells me it's a few things, cats clogged, possibly this fuel module, coils need to be replaced but it's odd all those threw a code all at once.

UAHogsF150

Lean on one and Rich on the other could mean 4 of your cylinders are consistantly out of timing due to defective phasers. Check the drivers control module first. If its fine, grab some rubber grommets or something to prevent its aluminum body to sit against the steel chassis.