Did you just install the TB spacer? If so you might want to check all the gaskets and make sure theyre not leaking. You can do that by taking some carb spray and spray it around the TB to see if it makes a difference in idle quality.
2000 jeep wrangler SE 4" super lift, 33" interco trxus sts tires, 4.0L TB, TB spacer, airaid intake
1993 subaru legacy turbo