Dirty tank or bad fuel pump

[kowalski]

did you read codes?

have you noticed any broken rubber hoses around engine?
did you lift of the airbox at any time, when refitting maybe airbox not sitting right ontop of MAF?

maybe bad spark plugs?
maybe bad coil packs?
maybe bad earth strap?

check with flash ligth if you notice anything strange around engine?

[MikeJM]

I've done everything you mentioned. Computer doesn't show any trouble with around the engine. The only trouble code was the the fuel pressure fault. I'll lift it up tomorrow and see underneath. Maybe the pump relay is also going bad.