Originally Posted by andrewwynn

Are you getting any other codes? Or: have codes started to migrate to particular cylinder? If you get enough misfires on a cylinder the computer will shut off that cylinder and the car will have little power and shake like crazy.

Wife's car we as only tripping misfires a couple times a week and an hour or two of driving with the cleaner seems to have done the trick. Your symptoms are 3-4x as bad and you've driven not enough to even get the temp to equilibrium. That said, I also replaced the two coils from the cylinders that acted up the most. So keep reading codes and see if you can find a cylinder that misfires the most is likely a weak coil.

Also: take out the plugs and clean them if they are gummy.

Originally Posted by andrewwynn

Have to drive to work the injector cleaner through but at constant higher speed where it won't miss.