fire up ur car, put some in a vacum line (brake booster) while somebody holds it at 2,500 rpms. let it smoke then stall out. then let it go for 15 mins. it will freakin get rid of everything! then fire it back up and drive for a while. it will smoke for about 45 mins but u will notice the difference. there is other ways. if u put it in ur oil it cleans but u gotta drop the pan. all of the grime will go into ur pan. helps fuel system too.
If your exhaust tip is larger than your cylinder bore, then you are a Ricer.