Recently my 2009 f150 5.4L has been great for a few days then had codes on others. This has been going on for about a month. The codes im getting are cylinder #8 missfire and both upstream o2 sensors. Has anyone had similar problems? And how do i fix it?

 

I'm not trying to beat you up, but:


For me, if not for most other members, it would be very helpful to know a little more about the environment before making a very meaningful suggestion - outside some of the lame, simple half cocked shotgun responses like "replace spark plugs".


What codes? There are several different ones related to ignition coils, wiring faults, and misfire profile, not to mention a bunch related to O2 sensors that provide some direction to go looking for causes.


How many miles on the vehicle?
How many miles on the present plugs?
What is the 'freeze frame' data?
Anything else been done/changed lately?
Any other symptoms - oddities?
Have you been clearing codes? How long ago?


Then someone might be able to suggest direction on "how do i fix it?"