Code P0133 keeps coming back

[Layla11242]

I've got an 03 LS and for about a year now I've kept getting the code P0133, it goes away on its own sometimes but never fails to eventually come back. I have replaced all four O2 sensors and cleaned the fuel injectors, and the car runs fine...
Anyone have any ideas what else this could be?

 

[joegr]

You probably need Forscan or similar to dig down to the details of what is happening.
Also note that the LS does not like most aftermarket O2 sensors, including Bosch.

 

[Layla11242]

You probably need Forscan or similar to dig down to the details of what is happening.
Also note that the LS does not like most aftermarket O2 sensors, including Bosch.

Thanks, I put the ford motorcraft sensors in but thanks for the note. I'll give an update when I get this figured out.