so i have a pretty much stock ls/vtec and the other day i downshifted and about ten minutes later it sounded all bogged down, back fired a little. and now its smoking more than usual. and i can always smell a little gas when i leave it sitting at idle. and cylinder one fouled up my plug, all others look perfect.

but heres the thing, it still drives fine, (meaning i can drive it throughout all the gears, vtec still kicks, etc,) i have just lost noticeable power. (a buick regal beat me .....)

not sure where i should start looking first. i mean it used to smoke a little which is normal with ls/vtecs.

any ideas anybody?

 

Probably running too rich, which isn't a problem in itself, but if it's too rich it will run funny and smoke badly, plus backfire. Backfire could be caused by other things as well, but your engine would be running crap. Do you have any trouble codes? If your check engine light is on, your ECU will be running in limp mode and being "safe" slow. Also, what is the condition of your catalytic converter?

 

so its freaking cold today so i decided to pop the hood and let it run a while and so i hit the gas and SURE ENOUGH the Header at the exhaust manifold has a crack in it right at the weld, so that explains the booged down sound, and could explain the "more than usual smoking problem"

So i will just have my bud weld that crack shut. the smoking is getting annoying too so i will still investigate that further

 

So it is black smoke? Correct?