It never made the blunt noise until after I put in the exhaust and it just shoots down to 250 RPMS for a sec.. It then jumps back to 750.. What is even weirder is when it does that, and I have my foot on the cluth, it just totally stalls out.. Do you know what that could be from? I think the noise is coming from the engine(?) and it only last for no more than 3 seconds when the engine is "de-revving".
