This started a couple of weeks back. It started with 3 codes, a misfire, bad coil and stuck rich. I have since done a tune up replacing all the spark plugs, the bad coil and even the O2 sensor. It is now at a point where the CEL is not on but it still throws the P2196 with a brand new o2 sensor just installed. I am stumped as what I should be checking for next. It seems to run ok but idle is not as smooth as pre-codes.

The truck is a 2006 XLT. Any suggestions or help is greatly appreciated.

 

Don't they have 3 o2 sensors? Did you replace them all?

 

Actually has 4.....the code seems to imply Sensor 1 Bank 1 which i believe is the upstream one on the passenger side. That is the one I replaced.

 

You may have an injector stuck open.

 

Is there a way to test for that?

 

I'm not sure of a testing procedure and my manual is at home. I also ran across this. Ford Fuel Injection » Fuel Injector Cleaning

Pulled this off E-How............
EFI Injectors

Start the engine and verify the injector operation. If the car does not start, have someone crank the engine. Use the tip of a mechanic's stethoscope to check the injector's operation. Also, you can place the tip of a long screwdriver against the injector and your ear against the screwdriver's handle. You should be able to hear the injector clicking, meaning the injector's valve is opening and closing. If the injector makes no sound, it is not working.

Unplug the injector's electrical connector and check the unit's coil resistance with an ohmmeter. Set the meter to a low resistance range and touch each electrical terminal on the injector with the ohmmeter's leads. If you read infinite resistance--no resistance at all--the injector's coil is opened. If you read zero resistance, the coil might be shorted to ground. In either case, the injector should be replaced. If you read resistance across the coil, go to the next step.

Connect a noid light at the injector harness connector--see the Tip section for more information. Start the engine and watch the noid light. If the noid light flashes, the injector is receiving power, and there might be a failed component inside the injector. If the noid light does not flash, the wiring harness or control module is not supplying voltage to the injector. Take your car to an auto shop for further troubleshooting.

Check this link for injector issues. Looks like '05 and early '06's are affected.
https://www.ford-trucks.com/forums/8...-warranty.html