Hi all, today I was leaving the dealership and merging into traffic when I heard a "ticking" sound (maybe 4-5 in succession) and noticed a puff of black smoke behind me. I was in 2nd gear at 4k rpm when I began boosting followed by the ticking sound during wot. Does this appear to be engine knock causing a rich mixture and should I be concerned or is this typical from time to time? The engine is stock with no modification. Thanks in advance.