I've been gettin a lot of misfire I have a volvo s80 2.9 engine non turbo 1999. Cylinder 1, 2and 3 spark plugs were all full with combustion. I replaced them with new ones and also switch the coil pack to cylinder 4, 5, and 6. Within 30 min the same thing happened on the same side. So I know the coil packs are working. What can my problem be. The obII gives me the code of p0134, p0300 and p1174.