Hi, Just after some advice. Iâ€™m looking at getting a Yoshimura TRS slip on exhaust for my 02 F4i. At this point in time I canâ€™t afford to get a power commander or a tune. Some threads Iâ€™ve seen say that the exhaust alone will be fine and other have said that it will cause flat spots or poor performance in the lower ranges. Just wondering what peoples experiences are with this?