Passat 2001 2.0se.... sluggish engine cuts out at med/high revs

[Guytheflyguy]

I have a Passat 2.0se 2001 model, petrol engine, which is now generally sluggish, not responsive and will cut out above 4000 revs. After which, I have to restart the engine. Having had it in the garage recently, they replaced an air hose to the engine and this resolved the issue for a while, but returned a month later.

The ECU returns a message, which reads something about an "torque limiter exceeded". engine also seems to be misfiring

Any help or suggestions much appreciated. Thanks