Had my s3 re-mapped about a month ago and then last week had the cats taken off,since the cats were replaced for straight through pipes she is smelling really rich..???..is this right
From EssThrees testing chaging from the standard cats to miltek performance cats gained nothing, so going decat will probably add nothing. Then there is the potential emission problem come MOT time. Just not worth the money or hassle if you ask me.
I asked this question a while ago, depends on engine code but i know BAM engines are a pain to decat, even if you do decat you wont see any gains unless your running a BT and then its only going to be a small gain.