So the car doesn't want to pass emissions.

4 out of the 6 monitors do not want to set.

There is no codes and no check engine light.

I hooked up my autoenginuity scan tool and bank1 sensor 2 appears to give no feedback. Other sensors work fine.

Now with the car running and the live scanner plugged in, I disconnected the plug of the downstream sensor that I suspect is guilty and the value reported by the other one disappeared. So at first I thought that i got them mixed up, but when I plug it back in and disconnect the other one the same thing happens. Are they on the same circuit?

 

Tell us which 4 monitors won't set? How much have you driven the car? Some of them take several drives to set, like Evap system and O2 efficiency (re: the drive cycle). If they won't set in a "given" time, the CEL should come on, with codes.

Of course you need feedback from all 4 O2s, otherwise several codes could (should) eventually appear. Make sure the connections are good, the O2 plugs fully seated. If you have one dead o2, I suspect that could cause failure of several monitors.

I don't know if continuity between both sensors is required or not, but I tend to "think" not.

 

The only ones that set are the oxygen sensor monitoring and EGR.

I did more testing today and the dead sensor came to life but only at WOT.

I ordered a new one from Rockauto for $58.

I was reading the service manual and it seemed like all of them could set after a proper drive cycle.

I have several newer jags (2 '98 and 2 '06) and when things are not right the CEL is on right away. With this xj6 it takes forever.

 

So I changed the faulty o2 sensor. Reading are now showing. Drove the car for 2 days, city and highway. Went through more than half a gas tank and the monitors still won't set. What's going on? There is no codes and no CEL.