Does anyone know if the xb has one?

Yup, it's behind the intake manifold...

Does it use a crank or cam sensor?

is there a check engine light on?

No, I just wanted to know. There is nothing wrong with my car.

Yup, it's behind the intake manifold...

Yup, he's right. It's a big job to get to. It's right above the oil pressure sender. The knock sensor doesn't use either the cam or the crank. It senses the preignition in the cylinders and retards or advances the timing through the ECM.

In the service manual, it tells you to take out the airbox and intake manifold to get to it...