A week ago my car without warning decided that it was no longer capable of 300 horsepower and reduced itself to an unresponsive shuddering mess at anything past half-throttle.

I had replaced a hose a matter of hours before this occurred, but after spending far too much time ruling that out (I was convinced I must have caused it so I retraced my steps several times) the next course of action was to change the spark plugs… it’s difficult to get this sort of thing done during the week, so I had to put up with the shadow-of-its-former-self for several days before doing this.

The old spark plugs were indeed pretty well worn and the gap was twice the distance of the new plugs, but replacing them didn’t fix the problem. Having wasted too much time already, I took the car into the mechanic and left them to it. Turns out I was close - the problem was the coils, which basically convert the car’s 12 volts into a stupidly high voltage (over 35,000V) so that the spark plugs can do their business.

My assumption is that allowing the spark plugs to age for too long was what fried the coils; it seems logical that an excessive spark plug gap will cause the coils to do more work which resulted in their demise.

Moral of the story? Check your spark plugs. If I’d spent $60 replacing them a year ago I might have saved myself $550 today.

On the bright side, though, my car feels awesome again.