Fault code

[Don]

I got a fault code today on a 2000 Disco

Code PO-174

02 sensor sensor system too lean fault Bank B

It is not for one 02 sensor,said sensor system.

would any one know what this is?

[Mjollnir]

There are two exhaust banks, A and B. Each bank has two O2 sensors, one upstream and one downstream for a total of four. If the codes were not diagnosed with the electronics required for Land Rovers, you may get an incorrect notice.
I am assuming you did not use a LR scanner, as the sensor scanner said it was not for one O2 sensor. If you went to an independent LR mechanic with the authorized scanner, you would get exact codes for each O2 sensor that failed.
Bottom line, you need two new O2 sensors for bank B, but I would confirm as soon as possible.

[Don]

There are two exhaust banks, A and B. Each bank has two O2 sensors, one upstream and one downstream for a total of four. If the codes were not diagnosed with the electronics required for Land Rovers, you may get an incorrect notice.
I am assuming you did not use a LR scanner, as the sensor scanner said it was not for one O2 sensor. If you went to an independent LR mechanic with the authorized scanner, you would get exact codes for each O2 sensor that failed.
Bottom line, you need two new O2 sensors for bank B, but I would confirm as soon as possible.

Thanks Thor
I found the problem,the big air hose coming from the air filter box the one withe the elbow goinginto the plenum was not on secure,the clamp was not in the chanel,fixed with my trusty screw driver,and all seems to be good. Thanks for your input. Don