2004 S40 Engine Shaking + Try Slow down or Shift up

[Volvo-ed]

Hi!
New here and I hope you can help me out here. I bought a Volvo S40 2004 last August. And today while driving it, i got error "try slow down or shift up" with red triangle and also engine light blinking. Car engine was shaking as well when slowed down or accelerated. I came home and searched on web found put that it could be a spark plug or ignition coil problem. So i went to my mechanic he checked it and I got following codes
ECM 3503 - misfire, cataytic converter damage
ECM 2600 - fuel pressure sensor
ECM 261A - fuel pressure system
ECM 3200 - ignition coil faulty signal
ECM 2000 - Engine coolant temp sensor

So i replaced spark plugs and ignition coils (kinda emptied my pocket) and im still getting all problems/codes mentioned above. Checked wiring, fuel injector, etc. Everything is OK. but same engine shake and "try slowdown" error continues. No fix so far. So i just got appointment from volvo workshop. Going there tomorrow. Whats your thought about it? What can be the problem here? Mileage is at KM 130k almost. Thanks and sorry for long message.
Thanks
Eddy