My Car Is Missing At Around 2k Rpm! Any Ideas Would Help

[2003sonicblue]

sometimes at idle my car will idle roughly and when i get up to about 2500 or 3k rpm it starts bogging down real bad and missing. its mostly only when i get to a steady speed. it spits out alot of black smoke when it misses also. does anyone have any ideas at all? it only does it sometimes. and it cant be bad gas please help me

 

[Juiced-03]

Sounds like spark plugs. What kind are you running? And what gap?

 

[2003sonicblue]

not sure on the plugs. only mods on the car are off road h-pipe and dumped flows. could it be the o2 sensors? or should i check the plugs. how could i tell which one it is? at wide throttle it runs perfect. only at idle or steady speed or slow accel it cuts out

 

[FireRed04Vert]

Doesn't sound like plugs to me. It really doesn't sound like O2 sensors either, but I guess it's possible. I had similar drivability issues with a KB CAI and junked it. I wonder if its not something with your MAF sensor.