Stalling at WOT
So, 06 Cobalt, 250k+ miles. Problems began a couple weeks ago. Car suddenly began running really rough one morning. Barely idle, had to really slip the clutch to get it to take off, etc. I had a new icm and coil pack on my shelf from a few years ago, threw that on, (after replacing the fuel filter, to no improvement) and the car ran great agian!
The next day, it died, just shut off on my way home. Had it towed, turned out I hadn't plugged the icm in all the way, and it was loose (felt like an idiot!) plugged it in, again, car ran great!
Ever since, though, the car will randomly die, and take several attempts to restart. If I go to WOT, the car will stutter, and run extremely rough. Almost like it's in limp mode, but I don't get the message.
The cel will flash, indicating severe miss fire, but the only code is P0300, which doesn't help much. I can clear the code, restart, and it's all good again.
(I did pull some throttle actuator control code once, unfortunately I didn't write it down)
Anyone have any ideas?