long story short. i threw a rod through the block a few years ago, replaced the engine (d15) and ever since it hasnt ran 100% right.

i didnt change anything . switched everything from the blown engine to the new.

i had the head off not too long ago to put on a new head gasket and everything looks fine no burnt valves or anything.

at idle it pops ( small backfire ) and if its cold it sounds like a build V8 big block ( kinda cool ) it will rev up to 3k then fall to about 10rmp and almost shut off.

while your driving you can feel the car pulse a slight bit . it runs fine and hasnt caused any trouble i just figured you guys might have an idea or guess. bad o2 sensor?

http://s30.photobucket.com/albums/c3...rent=029-1.mp4

 

anybody?