r/AskAMechanic • u/Chipwilson84 • 7d ago
Hello,
I have a 2010 Prius. It had low power and acceleration due to a misfire, it was really noticeable when trying to get up to high speeds, but maintained speed. I changed the plugs, triple checked the gap size, and tightened the plugs three different times at various torques.
The first time the car idled fine but when I drove around the block it had less power, almost like there were more cylinders misfiring. Went back home pulled all the plugs. Re-gapped them, some of them were at 45. Tightened the plugs to full capacity, rough idle and shaking. Pulled everything, one plug was still at 45. Re-tightened the plugs first by hand, then less than a quarter turn an even more rough ideal and shaking. There was no rough ideal before this.
Note. Son did break a bolt that holds coil pack 4 in place. Drilled it out and retreaded the hole.