1990 Olds 98 codes

I was giving my car a tuneup and ran across the following codes when checking the Service Engine Soon codes. Code numbers are 24, 41, and 43. In my manual, code 24 is the VSS but I can't locate it in the book or on the vehicle. Does anyone know where it is? I'm not sure about codes 41 and 43. I changed the O2 sensor, plugs, wires, and ICM. The car is hesitating at 40-55MPH when at running temperature after changing the plugs and wires, which is why I changed the ICM. I also cleaned the MAF body and sensor. I have a new Throttle Position Sensor but haven't changed it yet (waiting for a tool for access to it.) Am I overlooking something? Would changing the coil assembly help?
Thanks, Jason

41 coused cause the symptoms, it refers to the cam sensor circuit, the sensor could be bad or the magnet fell off the cam gear. If the speedo works ok leave 24 alone for now, the 43 may have been caused by you old icm.