My only experience of exhaust and the pors and cons are from motorbikes.. I know when I put a race can on my fireblade it was advised that I get the ecu remapped and dyno the bike to avoid damage to the motor due to it running leaner than with the standard can on.. Is this the same for cars? Also any suggestions on a good back box that will not drive me up the wall on my 15 mile round trip to work on the motorway..