Re: reverse polarity
Cat rattle may be there but you can see the tach drop when it happens so is definitely a misfire. Now the question is "why" ?
For instance if you rev it in neutral then let it drop back to idle does it go away or come back ? When driving does it feel down on power or rough when accelerating particularly around 50 mph/80kph ?
Did it happen suddenly, of has it been coming on for a while ?
Does the exhaust tip have oil in it ? (Looked shiny/black in video).
Hate to be asking 20 questions but have to narrow it down. That video was brilliant and a real help. Thank you.