Car only has header and AEM intake. No further modifications. Use Amoco 93 all the time, change oil every 3750, fluids are topped off.
Car has 236,000 miles on it. Yes, alot. Runs perfect except the following recurring problem.

History:

When car had about 100,000 miles on it, I was cruising down the NJTPK at about 80 in the fast lane. Suddenly the car just bucked, then tries to stall. Throw it into neutral and the rpms dump big time. Car stalls, I pull over clueless. CEL light is on. Turn car off, and restart. It starts right up like nothing happened. Doesn't happen again for another 10,000 miles. This time, happens again, cruising along, maybe 65 mph. Car starts to buck, then tries to stall. I put it into neutral, rpms dropping. I put my foot to the floor and I can hold the rpms to about 3000 but it wants to drop like a stone. CEL comes on. I let go of the gas and it stalls. While still coasting, I turn off the ignition and start up the car in neutral. It was like nothing happened. Resumed speed. Noticed something new. Whenever this happens, my idle is all buggered up and starts to bounce while waiting at a stop light. I have to wait until I get home and turn the idle screw down. This kind of problem happened intermittently for the next 100,000 miles. Then 2 weeks ago, I started the car on a damp day in the parking garage. Put it into reverse and she bucked a little, the CEL came on and the car tried to stall. I turned it off and on again, since this always worked before, and it continued to fight me. For the next 14 miles of my 47 mile commute, she kept doing it. Eventually it stopped and the idle was high again. I adjusted it down, yet again. Now, about 3 times per commute, each way, she will just buck for no reason. Won't stall, no code. Just cruising and then buck. Maybe even buck, pause, 2 more bucks, then resume like nothing happened. Bucks hard enough to throw my head forward. Anyone have a clue? I have a jumper in my car at all times now, ready to pull the car over as soon as I see the CEL, because it erases it once the car is turned off. Hopefully I will catch it before it gets too far into winter.

Help?

Jason