According to the '93 factory shop manual, the voltage at idle should be between 0.2 and 0.74 volts (engine off), so I wouldn't expect 0.41 volts to have set an error code, but make sure the measurement is made when the engine is warm.
I don't believe that the TPS on the '93 is adjustable like the older models were. If yours is adjustable, the 2 mounting holes will be ovular rather than circular, and you can adjust it to a slightly lower voltage at idle. If it'* not adjustable, check the wiring to the electrical connector, and if that'* ok, you may need to replace the TPS sensor.
'99 Bonneville SLE, white, 112,000 miles
'02 Park Avenue Ultra, white diamond pearl, 88,000 miles