Black93LX

anyone know if a 93 LX has a 3 way catalytic converter? the chilton says only 92' and up VX models have an EGR system, so is the cat what controls HC, CO and NOX levels coming out the pipe? my car failed smog on NOX (way high) but was way low on everything else so i had it repaired for emissions and the mechanic said the O2 sensor was bad so they replaced that and now all gases are high and the car is NOW a gross polluter, he says it needs a new cat but im wondering if i replace the cat if all the gases will be in check? thanks guys.