Well....if its a 400E, the surging could be something as simple as a dirty fuel filter.
The throttle response would have me worried. What you call TPS, they call the ETA.
The MAF sits on top of the manifold (the filter housing sits on it). It is expensive, and in some instances can be cleaned with specially made cleaner.
It could be another victim of low quality wiring harnesses. The insulation on these substandard wires, falls off over time, creating sometimes temporary shorts and whatnot.

If you do a search on ETA and MAF you will find all kinds of info.

As Dean said....state the year of the car, for further help - there is further diagnosis available on those cars.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D