Can someone tell me if the power stage unit for cylinders 1, 3, and 5 is the one on the front side of the intake (facing the front of the car) or the one on the back side facing the firewall?

Thanks!

 

What is a power stage unit?

 

The power stage (I think some might call them the coil control modules or electronic coil modules) are electronic modules that translate the ECU firing signal to the coil packs (I think they generate a higher voltage but not sure). There are two of them and they are small, black modules (~ 2"x3") that are mounted with two small bolts on either side of the lower part of intake manifold. They are identical and one controls coil packs 1,3,5 and the other 2,4,6. You can see and access the front one easily, but the rear one is more dificult.

Power stages are talked about somewhat in this thread that you posted on:
https://volvoforums.com/forum/showth...ht=power+stage

I have a similar problem (mine is misfire on #3) and I have eliminated the coil packs and plugs. I have a spare power stage but wanted to know if I need to swap out the front or rear one.