Q: Code P0451

P0451 will set if the PCM (powertrain control module) detects an incorrect, erratic, or otherwise improper voltage signal from the evaporative emission control system pressure sensor. The underlying cause is usually due to a defect in, or damage to, the gas tank, a problem with the fuel tank sending unit, a faulty fuel tank pressure sensor, an open or shorted fuel tank pressure sensor circuit, a faulty canister vent valve (uncommon), or a faulty PCM (very rare). Inasmuch as there are usually no discernible or outward symptoms, other than the Check Engine Light illuminating, some vehicle owners assume that a P0451 code is not a serious issue and that it doesn’t need to be resolved until the vehicle is due for an OBD-II emissions test. However, the vehicle malfunction reflected in the code can result in significantly lower fuel efficiency, and it can trigger other problems as well. Thus, it’s important to resolve it before it costs you more time and money later on. To have the issue identified and resolved, the recommended service is a check engine light diagnostic. If you request that service, a certified Mechanic, dispatched by YourMechanic will come right to your location, will get this resolved for you promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.