P0198 oil temperature sensor?

It should be on the left side of the engine about 1/2 way down the engine block next to the oil pressure sender. To the rear of the alternator and just below it. Just a bit above the cooler. Tucked in below the intake manifold behind all the hoses.

Would going threw the wheel be the best way to get to it

The left side of the engine is the side that is next to the radiator. You can get to it easier from under the vehicle as it is in the middle of the "front" of the car.

Thank you

STEVE W. is one of our best! Pleas let us know how it goes :)