Resolved 2gNT 98 RS idle problem and exhaust smoke

[navihawk]

Hello everyone. I just bought a 98 eclipse rs a few weeks ago and started working on it yesterday. I changed the timing belt, serpentine belt and oil change, and spark plugs. Before i did all that the car started to idle bad, very rough and sometimes when i would start it it wouldnt start, and when it did start it would idle less than 800 and would die, and turn back on, and off, and on, and off and on and it would do that a few times until it would die, I woudl try to start it and it wouldnt start, and from the exhaust it looked like it was shooting out some ashes, so pushed start it and worked fine, but it has some dark smoke. Now after all that i took it for a test drive and it would turn on and idle high, bout 3000 then go down to 2000 or 3000, and after a few minutes it would go down to 1000 or die, turned it back on and it sounds very rough, and it sounds like a mazda rx 7 rotary. When i give it gas at like 4000 + rpm it shoots out a lot of smoke, and it smells like fuel. Here are 2 videos of the car with the problem. Help ###. The passenger side mount it bad and new one is on the way.
YouTube - Eclipse idling problem

YouTube - Eclipse dark smoke

I was looking around the bottom and pulled off the o2 sensor that is right below the headers. I looked to have something broken inside. I shook it and it rattles a lot. Is it damaged? would that sensor affect fuel delivery?

 

[navihawk]

Well found out what problem was, all by myself!
I searched a lot on this website and didn't find a lot of information on that, so i decided to post a thread here. Wow almost 3 weeks and no replies? That's very helpful.

Turns out the upstream O2 sensor was destroyed. That took care of the smoke problem, and the "skipping" turned out to be a bad throttle position sensor, which was cutting off fuel and turning it back on quickly.