Why does my car idle fluctuate up and down after it reaches running temperature

What is your question?

When you first start it it runs great. After it warms up the idle starts sputering up and down wanting to stall.

What makes this problem better or worse?

Its only bad when car reaches running temp

How long has your 1994 Toyota Celica had this problem?

A few weeks, it started after we replaced EGR parts