It depends. All I had to do was extend my o2 sensors and I was check engine light free. I'm sure there are threads on here on how to do it. I also recall that FI markets these as being CEL free. Send Tony from FI a message here on the forum he is kickass
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|BW S259 Turbo|3" Downpipe\Exhaust|ID1000|AeroMotive|Tial|EcuTek|BC BR|S0-4|MaffFab|
MKGs-Single-Turbo
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