'08 S80 3.2 fluctuating idle and loss of power under any load

[LanceALatte]

A few nights ago after I started my 2008 Volvo S80 3.2 and got to a major road, making a left the engine cut out and the more I pressed the accelerator, the faster the car was slowing down. It limped home erratically. I then checked the battery, replaced the crankshaft position sensor, and fuel pressure sensor, and it seemed to help a bit, but still fluctuating idle, always cutting out, sporadic burst of power, and occasionally dying. After replacing the 2 parts, I was able to do 50mph instead of 8mph, but I felt like driving it even after was perhaps harming the car. It's a front wheel drive. I checked to make sure the intake tubes and air filter box were all snug, and I'm at a loss. No check engine light so I have nothing to go on. It doesn't sound like it's misfiring at idle. When in gear and going is when the cutting out and sudden surges occur with acceleration. I have an Autel MaxiCOM MK808 OBDII scanner, but no check engine light for codes as of yet. I don't know how to use it to obtain relevant data at this point without a code to pinpoint. Any ideas?

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