As far as I know o2 sensor after cat has nothing to do with fuel to air ratio that is a job of first o2 sensor so even if second one failed it would not cause engine to overfuel and make problem with emissions
Oh, if that is the case i will get some leds. Since i am in that kind of work shouldn't be that hard. Which color did you choose? I am thinking red or white
Does anyone k ow what type of bulbs is used for 197 speedo and ac display? I can't find anything on the internet which is strange, can't be the first one to want to change them
Many thanks in advance