You've replaced the obvious ignition side stuff other than the power stage, which is more often associated with a no-start or stall when it goes, so I wouldn't get too excited about that just yet other than cleaning up the connector. Closest ignition symptoms I've had to yours are a loose spark plug boot not making a good clamp contact on the spark plug cap -pushing it down would temporarily make a diff.

Bad hesitation during heavy acceleration, but being able to feather it up to higher revs and have it running half-normal really smells of fuel starvation to me. I'd add a new fuel filter to your maintenance item list. IMO your symptoms don't really match air starvation, but you should still check your air filter as a quick and easy thing to do.

If the problem continued I'd then want to check the fuel rail pressure (in a pinch, a tire gauge can be used on the Shrader valve to get a crude reading, you want to see in the order of 25-35 psi, not 10-20). I might even go so far as lifting the fuel rail and wanting to measure injector fuel flow into cups to make sure they're flowing evenly.

I wouldn't worry too much about the fuel pump or fuel pump relay. They tend to either work or not work, so are most often associated with a no-start. In the later B230Fs they changed the fuel pump relay from the tall white relay (middle row left) to a small cube relay (front row, second from right, typically blue, green or even black). The B230FTs kept the old white relay on the left. Hella is considered a decent aftermarket brand for the cube relays (Streibel for the white ones).

It's almost like you're running in limp home mode. I'd thought about adding a failing MAP sensor to your suspect list, but I don't think that matches your symptoms of being able to sustain a higher rpm. You've got a Check Engine code going anyway from the O2 sensor, so wouldn't know if limp home mode was happening unless you saw other codes.Just for jokes, disconnect your MAP sensor to force limp home mode and if the stumbling under acceleration doesn't get worse then you know that's it.

Similarly, a 2-2-1 O2 sensor code does not set limp home mode, but at some point you need to deal with that outstanding O2 sensor problem. O2 sensor issues generally affect fuel economy, not hesitation during acceleration, but it could be a contributing factor. If the Check Engine light comes on almost immediately after starting and letting it idle then I'd suspect the O2 sensor and its wiring, not an air leak. I assume there are no other codes on ports 2 or 6 (each side can store up to three different DTCs).

Much further down the suspect list would be the knock sensor. They only set a code when they outright fail or are accidentally disconnected. Is there any pinging during acceleration?
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now