Thanks for the reply. What u-joint are you referring to? Having pulled the engine and transmission out, I’m not aware of any u-joints but it could certainly be there.
I replaced the rear engine mount and think I need to replace the front/side and the transmission one, but again, don’t want to just start replacing stuff randomly.
The slight stumble (and I mean very slight, but I am sensitive to cars that way) when driving makes me think it is in the fuel system or spark, or maybe a sensor, but just not sure. Both O2 sensors have been replaced, so I don’t think that is it.