Solving the car engine is an important thing and that is why,, you should take necessary step to make the car engine perfect. The car engine should be tested when any problem is found from the car engine. The car engine P3421 Code has found from the car engine and meaning of the helps to know the problem and location of the car engine problem. The right meaning of the code is necessary here but automobile dictionary meaning of the code may use for solving the car engine problem if it is necessary. However, when the car engine is fully ok, a test drive is recommended.