Doesn't the Cessna single engine fleet have a static port each side
The ones I'm aware of have only a single port on the left side.
db, with the Cessna and its left side static port I'd expect that a slip to the left would have the port seeing increased pressure, slip to the right reduced pressure. The question then becomes what does the pitot see? An academic paper says,
When the inclination of the flow exceeds about 15-20 degrees, significant errors will result due to the friction and boundary layer separation effects that occur. In these situations, the pressures sensed at the Pitot-static tube ports do not represent the desired stagnation pressure and static pressure. This is due to the fact that the Pitot-static probe is not a directional device, and so in unknown flow situations, a departure from the ideal uni-directional flow can result in very significant errors—errors which may be unknown to the observer due to lack of knowledge of the true flow direction.
The summation of all the effects you need to become a test pilot.