For a while now at WOT in first gear (A4), the car would bog just for a split second and do fine. BTW, this problem is all at ~5000+ RPM.

It was really bad once, then it seemed to go away. Now it's worse than it has ever been. When it starts to stumble if I keep on the gas it sounds almost like it's hitting a rev limiter, pop pop pop kind of sound, but it's no where near 6k rpm. It blows a huge cloud of black (rich) smoke out the exhaust.

I'm getting no check engine light, and I've checked the wires pretty good to make sure one isn't burned. I checked the egr valve, and checked the MAF sensor by pulling the plug and letting it run in speed density. The problem was still there. It seems to happen more frequently when the car is warmed up, like 180 degrees or a little more, but it still happens some when it's relatively cold. Has anybody had a problem like this before?

The fuel filter is new, as are the plugs. Should I go to a stealership and let them put it on an analyzer or what's the general concensus here?

Thanks for all of your help in advance.

 

Sounds like maybe your o2's are bad. It could be an opti but the black smoke and the fact that it runs ok when cold sounds more like bad o2's. Jason Cromer or Dal have then for $35 a piece. A regular dealer ship will want around $75 a piece for the o2's

 

Thanks for the reply. I replaced the coil this morning thinking about the possibility of heat soak and it seems to have more or less fixed it. I figured I'd change all the cheap tune up part stuff before I switched optis. Thanks again to all.