Torque converter problem?

I ve just had the torque converter replaced on my BMW 330CI. Since getting the car back ive noticed that the car seems to be running sluggish. On the motorway if iam driving along around 60 - 70 MPH and i put my foot easy on the accelerator there seems to be no response. The petrol gauge goes up but the rev counter stands still. Eventually the car gains pace and still drives superb at higher speeds or when i kickdown. There have been two codes recently pointing to the o2 sensor post cat bank 2 but i had one of these changed a couple of months ago. At the moment there are no warning lights on...iam hoping theres some sort of air leak and its not a transmission problem starts fine and idles fine changed the plugs but no change...any thoughts....

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: About Oxygen Sensors

[Wayne 962]

Hmm, if you've had the torque converter replaced recently, then I would take a closer look at that being the problem. On the freeway when you step on the gas, the engine will try to push the car faster through the transmission, which includes the torque converter. If there's something wrong with the converter, then I think you might see some of the issues that you're thinking you see. I would take it back to them and have them read the codes and drive the car for a while to see if there are any issues.

- Wayne