My issue is finally solved. The upstream o2 sensor was bad. Replaced the sensor and now it is running good.

I would like to know also about the headlights staying on also.

I did notice something to today when leaving from work. When it was cold start it has no power and then it stalled 3 times. After the 3rd time it sounded like it back fired then it ran normal again. I am confused.

If I idle it up by 100 rpms it will smooth out. I am thinking maybe a voltage regulator.

ANY IDEAS

I am new here and this is my first volvo and it has been a nightmare. I only have 97,000 miles on the vehicle. It is an 01 s60 2.4t with an auto. I have a surging idle and the lights will surge with the idle, it has a new battery so I ruled out the alternator. I had the original throttle body rebuil...