Set HC at the KEIII Audi 90 5Cyl. NG

Hello together Today at the MFK (i.e. in D TÜV) was a bit frustrated. The exberddäh said that the HC value was probably a bit high (AU), is also looked at. Apparently the measuring system with us in the CH from “Before the cat” on the gas recirculation has been changed times to measure on in the exhaust, what he then did and the HC value was at first over 100ppm. After a little higher idling he then sank to exactly 100ppm. Question where, ask such a thing? Is this the famous maggot screw (screw) behind the pressure selector? Then he still has track rod ball head and axle handlebar bearings with too much play and a brake disc. The shield plate on the cat too, is looser. Can this be fastened (screwed)? It gets pretty hot there.. Thank you for your tips already in advance..