I don't know how else to describe it. I started my car up with morning it was covered in frost. I let it warm up for like 15 minutes while I was looking for my dress shoes. I came back out and the car was just about to operating temps and most of the frost was starting to turn into water and run off. Hopping in I noticed the car was a bit like being in a old American car with the slight rock back and forth. I was like maybe it just needs to shake the cobwebs out. So I started driving. I quickly noticed the engine on acceleration sounded like a semi's j break. It didn't make a sound when I completely lifted off the gas or at idle, but the idea was still shaking. It idled perfect at 900 rpm the whole time. It only sounds horrible when the throttle is engaged. Also the back fire on down shifts where much louder. I don't know if it's a misfire or an EGR valve. I Though maybe a little water at first but after an hour both ways driving it didn't go away. If anyone has any tips or tricks it be great. Also it's a 95' 1.8L.