Violent Lurching in 1st and 2nd Gear

[SonomaGTLN2]

Hey all,
Just turned 90,000 miles on my 95 318ti, 7k after a headgasket change. Just today after a fuel fill up I felt a violent lurching about 2000-3000rpm in first and 2nd gear. Also had some lighter stumbling at ~5500 in 3rd. I am assuming i got a bad batch of gas because this car hasn't had any issues whatsoever since I replaced the headgasket! I am getting no CEL light on constantly but it does flash during the lurching and the RPM gauge wants to fall to zero. By doing the stomp test it showed the 1226 knock sensor code. Would a bad knock sensor actually cause such a violent lurch?

I have experience with E30 M42's and the only time I felt something like this was due to a bad coil driver in the DME.

[BRADESTAR]

I'd think the sensor is reading the problem.

The only experience I've had with "violent" losses of power have been electrical related. Fuel and Air seem to cut off smoother to me, but I'm jest guessin'.

Good luck.

[SonomaGTLN2]

I think its violent mostly because its in first and 2nd gear. Going with the process of elimination to see if I can sort this out without having to remove the intake mani to get at that knock sensor. Since I realize now the issue only happens when the car heats up, I'm figuring it is something related to the car running in closed loop, or wires/ignition. I'll post my findings here.