My Herky Jerky Cav!

[QCubed]

Yesterday morning, my 2.2L 99 Cav automatic seemed to misfire and was driving jerky. When idling, the engine seemed to surge, then almost stall, then surge, then almost stall, etc. I was on my way to an appointment and did not have time to stop so I kept going. Once the engine got warm, and I got on the highway, the problem went away. After my appointment (which didnt take long so the engine should still have been warm), the car drove fine. Then, starting up the car this morning, the problem started again, but was worse. This time it seemed to sputter as well. And soon the "check engine" light came on. I had to give extra gas to keep it going at normal speeds and I thought I could smell gas (probably because I was giving extra gas.) Once again, once the engine got warm, and I got on the highway, the problem seemed to disappear. I did a cursory check of the spark plug wires, and they all seem fine. Does this seem familiar to anyone else? Any ideas on what the problem might be?

[QCubed]

P.S. I should addd that I have had to use the car several times today, and so it has not had a chance to cool down. It has not been jerking, and this last time I went out I noticed that even the "Check Engine" light had gone out! So the problem, whatever it is, seems to be prominent when the engine is cold, and "silent" when the engine is warm. Any body know what the problem might be?

[QCubed]

Update:

I had a moment to open the hood and take a look around. I found that the cover for the air filter had not been screwed back on, so I have tightened it on again. I'm guessing it was left off from the last time I took it in for an oil change about a month ago.
- Could this have been the source of the problem? sucking in dirty air? The car does not seem to have gotten any better after I screwed the air filter cover back on.
- How does one clean the intake, MAP and Idle control valve?

[QCubed]

Update: I got a chance to look under the hood, and found that the air filter cover had not been screwed on, probably from when I last got the car serviced about a month ago. Could that be the source of the problem? I screwed it back on tightly. However, I'm sure stuff needs to be cleaned "downstream" after sucking dirty air for about a month. Can I find instructions on the net about how to clean the intake, MAF sensor, MAP sensor and Idle Control Valve? The problem seems to be getting worse though, as the car seems to sputter and miss ocassionally even when the engine is warm now.

Thanks to all who read and reply!

[QCubed]

Update:

From another thread, I learnt how to clean the MAP sensor, IAC valve and intake, and I did that. The problem was not resolved, although, the car seemed to have a little more power. So I took it in to the mechanic, and he read the OBD codes, and diagnosed a misfire. He replaced the spark plug wires and the spark plugs and that resolved the problem.