My buddies car is a 95 M6 formula. Was running fine yesterday and he did absolutely nothing to the car other than park it.

Fired it up today and it randomly will pop LOUD. Idle or cruising it dont matter. Normal exhaust tone, POP, normal exhaust tone... and it repeats this over and over no matter the rpms or driving condition the car is in. Like every other time i have a ignition issue i think of the opti.. this one seems to wanna point to it more for me simply cause the fact i have no idea what else would cause this other than timing/firing wrong time. any help would be appreciated

 

if its not throwing any codes...id start with the basics...check the spark plugs and wires first.