M.I.L eliminator necessary?

Your car doesnt go into limp mode because they are the rear O2's. So with MIL's you are just getting rid of the light on the dash. Tho when I bought MIL's after a couple days driving the light would still come on and I would have to reset computer. I fixed it with the Diablosport Predator. It allowed me to turn off the rear O2's.
 
Only vehicles equiped with OBDII (96-up) require MIL eliminators because they have O2 sensors after the cats. Most likely the cause of your 88's check engine light is a bad primary O2 sensor.