Anyone got any ideas on this weirdness! Car is an s3 8l (2000) . Decat, 007p, n249 delete and remapped. Noticed my maf readings where low on vcds (no codes though) and my mate had a brand new seat altea maf (chinese jobby) to hand so gave it a try and the car ran much better... easy then I thought, I'll grab a new s3 bosch maf job done. Before I bought one I tried another mates genuine cupra r maf seems as the engine is the same, logged his on vcds and the maf works fine but when I ran it on mine it drove awful! Things I noticed on my car with each maf : Cupra maf- Airflow waaay down to about 150gs (same maf reads about 210 gs on the cupra) After 4k the ecu drops requested boost progressively (limp?) but before 4k its fine and fuelling looked ok throughout Altea maf (wrong maf!) Below 2k its not as smooth but on a run airflow reads about 200gs and it pulls much better 2k upwards without ecu dropping requested boost Only thing is the stft goes to about -7 and Itft to about -15!!! Why would the car run much better with the wrong maf and fueling out! :-/ anyone?!