P3421

DTC P3421, sometimes indicated as P342100 is an OBD diagnostic trouble code indicating a manufacturer-specific fault with the vehicle powertrain (i.e. engine and gearbox). This code identifies an error with the auxiliary emissions system causing cylinder 3 exhaust valve control circuit/open.

One potential cause of this DTC code is a faulty exhaust valve. If the exhaust valve is stuck open, it will cause the engine to misfire and the DTC code will be set. A faulty exhaust valve can be caused by a number of factors, such as a misaligned valve, a faulty actuator, or a burned-out coil.
If the DTC code is set, the best course of action is to have a qualified technician inspect the vehicle and determine the root cause of the problem.

• P3421: Cylinder 3 Exhaust Valve Control Circuit/Open
• P3421: Exhaust valve control, cylinder 3 – open circuit
• P3421 00: Exhaust valve control, cylinder 3 - open circuit