Big problem?!?!? Plz help...

[FivepointOH]

I am about to do a complete tuneup on my car(oil, fuel filter, pcv, wires, cap and rotor), one of my dumps had fallen off and sometime around then my car seemed to have a clicking sound coming through the exhaust, it was no longer smooth like it used to be. I figured it was becuase of the dump, today I got a new one welded on and it still does it, I also noticed that the smoke coming out was black(maybe it's black because it's in need of an oil change?).... my question is what the heck is wrong with my car, why is it making this funny ticking sound and have a good amount of black smoke... it has a miss from idle to 2000 rpms, would this be causing the noise+black smoke? Is there something major wrong with it? I don't want to do a complete tuneup on it if the engine is dying or something....

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92 AOD GT, K&N, ram air, pulleys, 2 ch. flowmasters, 4:10's, shift kit, 1 5/8 mac longtubes and offroad hpipe 14.249 @ 97.34 mph before the headers and hpipe