My idle air intake valve has had to be replaced. Unfortunately the problem still exists. This happened within one month of ownership. My airbag sensors needed to be replaced about a week after the Idle air intake valve. After having the cougar for a week the flex pipe needed to be replaced. Fuel pump sensors and water pump sensors need to be replaced. My car is now having difficulty shifting in to second and third gear when coming from a complete stop. It bucks like it is a standard transmission and I am learning how to drive.
This car has serious problems. I always wanted a sports car, but this cougar has cost me more money than it is worth. They are horrible in the snow even with the so called traction control. I cannot wait to get rid of it.
Your transmission is probably failing. This is the same symptom as my daughter's 2k Cougar. The internal clutch in the torque converter self-destructed, sending fine friction material particles through the cooling lines, requiring the radiator to be changed as well. (Dealer said they could not be cleaned out.) Luckily the car was still under warranty. One dealer tried updating the trans computer, which did nothing. You probably didn't want to hear this, sorry.