Hello! I wanted to ask you what your experiences with “cheap” catalysts are like. At a well-known auction house on the Internet (E****) there are some offers of Kats around 100 euros. A qualitatively acceptable cat of a well-known manufacturer would cost about twice on the Internet. If one comes with such a cheap part probably over the HU? This is only in 1 1/4 year with the vehicle, but the regular error message of the car (P0420) is so slowly annoying. Would you get for the sale of the old cat and where do you sell such a part best? Thank you in advance for your answers!