Not knowing the ins and outs of the engines in the E46 but assuming that they are the same as those fitted to the E39.....

 

Having a look http://www.realoem.com/bmw/showparts.do?model=AM32&mospid=47638&btnr=13_0641&hg=13&fg=15" rel="nofollow - here it would appear that it is an electronic throttle.  You must have the M52TU engine, does the cylinder head front cover have a single bulge in front of one of the camshafts or does it have a single bulge.

 

M52 engines have signle vanos engines which have the single bulge in the cylinder head cover and they have a throttle cable.

 

The M52TU engine which was on post Sep 98 build date cars will have the double vanous identified by the large bulge in the cylinder head cover and have fly by wire.

 

Depending on your build date (check black data plate on inside of engine compartment) you may have either engine in your car.  TU was the technical upgrade given to these M52 engines. All it did was make the max torque figure 245Nm available lower down the rev range making it a bit more driveable than the non upgraded engines.  Didn't give the engine any more power or torque but variable valve timing on both inlet and exhaust camshafts, hence the change in cylinder head shape.

 

You can replace the throttle pedals easily enough on either type of engine.

 

Andrew

 

Edit to show link D'oh!