Skeet Skeet

So i was leavin work today and went to start my car and i noticed something was wrong with it as soon as i started it. It started to bog a lil bit. The rpm's wouldnt level out they kept on dropping to around 350 to 400 and then bck up to 700 or so like they should be. It drove home just fine except when i put the clutch in and let off the gas it dropped off again and kept wanting to die again but it drove fine and reved fine when ever i did give it gas. I was thinking it mite be the fuel filter but not to sure. Also the check engine light was off and it should be on right now. I just got longtubes installed with an off road y and it hasnt been tuned out yet so please any help would be greatly appreciated. Thanks guys

Skeet Skeet

Any help would b nice i dnt know what it is?