The B1604 Code is found when the engine of the car is verified by the machine. It is important to solve the problem of the engine. You can solve the issue if you use machines and you have necessary experience. Like the all car engines, this car engine system works especially established hydraulic lifters what is known as switching roller followers for the warning B1604 code intake and finish valves. The lifters can be distorted by disengaging an inner locking pin. The locking pin is detached using solenoids to alter oil compression fed into the lifter. You have to use manual to know more information.