Hey , well I've got a honda eg 1.5 vti. Basically this started about two days ago when I start the engine both when the engine is cold and warmed up it sounds like a subaru engine but when i rev it for a few seconds the sound disappears and the normal sound exhaust of the engine can be heard. What could possibly be the cause for this sound ? Also the car is stock except the cold air intake.

Spark plugs, the tension leads where changed about two months ago and both the distributor cap and rotor were changed about two weeks ago

 

Sounds to me like you have a bad head gasket and it's pushing coolant into the cylinders. After revving it a couple of times it pushes out and burns off the water letting it run normally.

The fast easy way to know now that you've driven it this way for a couple of days it to pull your spark plugs and check your piston tops, one or more of the pistons won't have carbon anymore as the coolant steam cleans the combustion chamber.

My 95 civic was doing this and after about 2 weeks, it was really hard to start in the mornings. #2 and #4 piston and spark plug was spotlessly clean while #1 and #3 had black carbon and the normal tan ash deposits on the plugs.

If you don't have coolant going into the cylinder then you have a misfire, but I am not sure how revving the engine would fix an ignition related misfire while I know if fixes the coolant in cylinder issue.