I have a de cat pipe on my exhaust system and gives the car a nice tone. Not too loud either, only issue is that the EML light comes on because of this. Cat bank 1 from memory. Stays off for a week or so them flags up the same issue again. I asked a local tuning company about having it mapped out and he quoted £150 And has said he can get a safe 280 bhp. My car is standard other thsn the de cat and although i would love the extra power i want it to also be reliable and certanly could do with out any more bother. Bam s3 with a recent new used engine on 79 k approx. I was really only intersted in removing the EML light as it bugs the hell out of me but the extra BHP is very interesting. Has any body got any advice ?? Thanks in advance !!