Hey guys, Friday I bought a used 09 wrx sedan. It had 27,000 miles. It came with an after market exhaust. Not sure what type. So I started the car yesterday after sat for a few days. A huge black cloud of smoke came out and filled up my garage. It smelled like burning oil but went away after 5-10 seconds. It has never done that before. I have only had the car a few days lol. Is it engine blow by?