This may be an old thread and i dont know if you've fixed it already or what but back when I got my SSEi it had the same problem with jerking while I was driving... It always seemed to happen right when the boost gauge was at 0psi or around there and it turned out to be a bad pulley. I'm not sure which one it was, my dad took it and got it fixed and it worked fine so you might want to check them. Hope this helps

new guy here with almost exactly the same symptoms just wanting to know if it ever got fixed?

This is a older thread, might be a good idea to start a new thread if your unable to find a fix.

just bought a '00 Bonneville SSEI all loaded up and it'* been OK, but it'* got the infamous clunks when steering: yeah, I'm going to lube the I.Steer Shaft, but more annoyingly it'* got this annoying jerking/hesitation thing when going up hills or slight inclines: step on the gas: takes right off and disappears. (no warning lights of any kind have come on in MIC)

I've read this WHOLE THREAD and still don't know where to start first: MAF,EGR, Cat Converrter, Pressure control solenoid,vac line, etc....got a real good and honest mechanic who has done plugs, wires, fuel filter, air filter, checked tranny fluid: ok, checked PCV: ok, and he also scanned the computer and it came back clean. I also had a real good tranny shop scan it while going down the road and it came back clean. He did detect a bad tranny mount than was replaced. Plan of action would be appreciated guys......