Suggestions..... if I may:

1. If you had the car serviced for that problem, and the original symptom is still present, they should service it under warranty..... specially after spending that amount of $$

2. The first item to do would be to check what the EEC is working with....... a DIY KOEO/KOER self test will allow you to check what the EEC is dealing with in terms of possible circuit failures, and prevent you continue replacing parts that may not need to be replaced.

3. Suggest to perform a Base Idle reset + a "Salt & Pepper" connectors fix.

LUK