I have been working a 2098 2096 for a long time , here what you need to check your muffler for any leaks , Vac hose around the motor , make sure you don;t have crack in the cats
, last one that fix mine, was the rubber rings or boots around the MAF or the O ring on MAF ,now if the rubber boots are not snug around MAF, then take them off and clean them real good , while you have that off check all vac hose , I have been good for about 9 months now with no check light,