For sale ER 4" high flow catted downpipe, it`s been used for 15K miles. Comes with mini cat for CEL fix and brand new BMW Genuine seal gasket. I never had problem with CEL unless i pushed RPM hard then "check engine" appears for 1-2 days and after 50-80 miles goes away by it self. Minor gas smell, noticeable HP increase, great sound when combines with sport exhaust system. Stage 2 tune is must for better throttle response and HP increase.
Feel free to ask if you have any other questions.
$400