Can't seem to get rid of this code p2195. I changed upstream sensors yesterday and it seemed like all was good but this morning the code came back. Truck is 2005 f150 4.6L. I recently changed MAF sensor. Gonna change the fuel filter in a bit and plugs. No vacuum leaks that I can find. Any other ideas?? Thanks

Edit: fuel pressure at idle is 39.5 and increases and decreases with load and vacuum

 

See attached.
Is the O-ring installed on the dipstick?

 

I believe the o ring is still on the dipstick

 

Code remains. I was watching the live data on the scanner and all the o2 sensors were functioning as they should. They weren't stuck on lean. So there's obviously something else at play, maybe the exhaust manifold gaskets are leaking??

 

That list I sent to you has about 20 items that are possible for a P2195. I suggest you look that over and check the most likely ones first

 

Check the harness near the exhaust manifold — the 4.6L wiring sometimes rubs or melts on the manifold heat shield or EGR tube.

You can also swap Bank 1 Sensor 1 and Bank 2 Sensor 1 to see if the code moves to Bank 2 (P2197). That’s a quick way to isolate if the sensor or the circuit is at fault.

 

I've replaced the front two sensors and checked the rear while doing so and they're all good. I was watching the live feed on my scanner and all the sensors are doing what they need to be doing

 

is the system in a closed or open loop? How are the fuel trims looking at idle,1500 and 2500 rpms?

 

You have a scan tool hooked up and are watching all 4 O2 sensors switch, right?
Can you do that? Do you know what I mean?
That is where you start
To determine whether the sensor is full of **** or the truck actually has a problem

 

If you run through those pinpoint tests for code P2195 in a PCED
They have you ohm out the wires back and forth from the processor to the bank 1 front O2 sensor
Then check the PIDS and watch the bank1 sensor 1 switch
That bank 1 front O2 sensor is referred to as O2S11 on scan tools
and
Bank 1 is always the bank that contains cylinder #1
When your truck actually has a problem, you'll see the bank 1 O2 sensor (in your case) never or rarely go over .5v on a scan tool PID
Go do all that and report back if needed