is this only after hitting a good puddle in the rain?

and what does it sound like when the cat falls off? the exhaust gets loud? or feels like its dragging the street?


if this only happens in the rain, id think your belts are getting wet, causing a belt to screech/slip and then a loss of power.

and like bill asked, what plugs did you put in? if your engine is stock your best off using stock iridium plugs. the air box dont count.