Why does P0325 code come with Circuit/Bank 1 not Bank 2?

[s199810]

I got a P0325 knock sensor circuit/B1 code. I understand how the knock sensor on my QX4 99 works and it seems to me there is only one knock sensor mounted on the driver side engine block (Bank 2, or B2) under the air intake manifold, but why does the P0325 code come with B1 not B2? Or, am I wrong that the QX4 or Pathfinder 3.3 L has two knock sensors? one on B1 and one on B2?

I replaced the spark plugs recently, first was Bosch Platinum which sounds very cool but the car stalled on road when waiting at intersection, embarrassing!!! , replaced the spark plugs with NGK the one in the owner's manual, it works good but occasionally the engine jerks during idelling, after running half hour or one when the engine is hot. Does the engine jerking during idelling and when the engine is hot have anything to do with the knock sensor? I bought a code sanner after replacing the plugs and found the P0325 code, so I don't know if this code existed before replacing the plugs or not. The engine didn't have any jerking in idelling before I replaced the spark plugs. After I replaced spark plugs with Bosch Platinum one, the engine shaked badly a few times, would the knock sensor be damaged because of this? I know you can't drop the knock sensor on the ground as that would damage it.

Any insights would be much appreciated.