Recently I developed flashing check engine light/misfire only during warming up the car. Misfire on all bank 1 cylinders which based on a research lead me to conclusion that hydraulic solenoids responsible for variable timing are acting up. Replacement was a fairly easy job and took me around an hour. After few test drives I've noticed car gained fair amount of torque in mid range. Misfire and check engine light is gone but it made me think that at this point solenoids on bank 2 might be somehow worn out and even without CEL they might not work up to the full potential. Does any body got any experience with that? What's your opinion?