sometimes when i'm cruising in 5th or even when i'm just going along at a constant rpm the whole car starts shaking. this is not because it's in too low of a gear either. i have an exhaust leak right now right after the headers but i don't have the right tools to fix it so i can't right now.

 

how bad is the leak? if it is bad enough to where you have barely any exhaust going through the o2 sensor on that side, that COULD be the reason

 

there's a gap on both sides and it's KINDA big... i mean you can tell there's an exhaust leak