Hello!

First off, I'd like to thank all of the guys here for the amazing wealth of knowledge on this board, I've learned TONS of information in the last 2 days and it wouldn't have been possible without them.

I just purchased my first F150, it's a '99 STD w/ the 4.2L. It's got 73K miles on the clock and I just picked her up yesterday.

My question is this, I'm getting 2 codes: P0171 and P0174. Lean on Bank 1 and Bank 2. Doing some research here on the forums led me down the path of possibly a leak at the Intake.

I checked the PVC tube as I noticed some oil buildup around the top of the valve cover, but the tube checked ok and holds air.

What should I be checking for?

Thanks!

-Brian

Codes:

-P0171: System Too Lean (Bank 1) (Powertrain, Generic)
-P0174: System Too Lean (Bank 2) (Powertrain, Generic)

 

You should be checking for vacuum leaks everywhere.

 

take a can of throttle body/carborator cleaner and spray around intake/ vacuum harnesses. inspect for exhause leak pre o2 sensors and check for stuck open egr valve.

 

Just wanted to update this thread, I poked around the intake plenum with some carb cleaner and found a leak. During the gasket replacement I discovered 2 extremely worn vacuum hoses. I replaced them as well as the DPFE Sensor (the hose barbs were pretty much gone on it).

Now she runs great, lots of power and no more idle/stumble issues. The CEL has stayed off since the codes were cleared.

Thanks again for the help, I really appreciate it.

Just have to adjust the rear brakes and go over the front end and we are back on the road.