Clean the throttle body and perform adaptation with VCDS.
Check the MAF. Do you have vag-com? If only a generic scan tool, see if it runs better with the MAF unplugged. Drive with it unplugged for diagnostic purposes only, DO NOT leave it unplugged.
Does the speedometer work? 16885 relates to the vehicle speed sensor (speedometer sensor) and has nothing to do with performance.
Any other faults?