Which oxygen sensors do I need to replace or do I need to do both the front or back ones? I reset the codes but it came back after a couple of weeks so I figure I'll go ahead and knock it out now. 2004 Disco with 63k if it matters any.

 

Have you done a tune up yet?
95% of all O2 codes on a Rover are because you need a tune up.

 

Did spark plugs and wires at 53k.

 

What wires did you use?
Do you remember?

 

Want to think they were Magnacor.

 

Ok, then replace both front O2's, clear the code and see what comes back if anything.