The Lambda shows in the lean, but acceptable range. The aftermarket Cats are marginal on a good day and garbage otherwise. Before doing that I'd throw an O2 sensor in there, disconnect the battery for awhile to clear the adaptives and give it a shot. In '95 O2 diagnostics were lousy, the sensor can be pretty far off and not throw a code. It should only run $50 or so to replace- I'd recommend the 1) O.E. or 2) NTK sensor, I've had mixed results with the Bosch sensors. O2 switching is very important to keep the A/F in the range(s) that allow the Oxidizing AND Reducing beds to work properly. HTH, Steve