car stalling and very sluggish

[troyounces]

Hello everyone,

I have a 2001 X5 3.0L. Two weeks ago my car stalled while driving in a parking lot at very low speed. I restarted it and had a check engine light. When I tried to accelerate the car gently (from stop) it would stall on me. When I accelerated harder the rpms would drop suddenly but the car would not stall. When driving the car felt like it weighed 10 tonnes and was having trouble accelerating. The next morning, I started it up and it ran fine.

The problem happened again a few days later. After reading a few threads I decided to change the Mass Airflow Filter. I thought it worked but it happened again yesterday. It seems that starting the car on a hot day, when the engine is already warm causes this - although it could be a coincidence, but this has been the case every single time.

I ran carsoft (which I just bought yesterday) and it said there is a problem with my oxygen sensor post catalytic. From what I have read, this would not cause these problems.

My guess is that there is a problem with the air/fuel mixture. Does anyone have any ideas what else I can check?

Thanks again.