OBD-II Generic Error Code P2142: How to Fix It

Q: Can I drive my car with a P2142 code?

You can often drive short distances with P2142 active, but it is not recommended for extended driving. The ECM may activate a reduced-power or limp mode to protect the engine, and your fuel economy and emissions may be negatively affected. Prolonged operation with a faulty EGR system can lead to increased engine wear and potential damage to catalytic converters. Address the issue as soon as possible.

Q: What is the most common cause of code P2142?

The most common causes of P2142 are a failed EGR throttle valve actuator, a short to voltage in the EGR throttle control signal wire, corroded or damaged wiring harness connectors, or heavy carbon buildup causing the valve to stick and send an incorrect high-voltage signal back to the ECM. Wiring issues and carbon buildup are the most frequent culprits before a full component replacement is needed.

Q: How much does it cost to fix a P2142 code?

Repair costs vary widely by vehicle and root cause. Cleaning a carbon-fouled EGR throttle valve may cost $100–$250 at a shop. Replacing the EGR throttle valve assembly typically runs $150–$600 in parts plus $75–$150 per hour in labor. Wiring repairs vary based on damage extent. ECM replacement, if needed, can cost $500–$1,500 or more including programming. Getting a professional diagnostic first ($80–$150) can save money by confirming the exact cause before parts are purchased.

Q: Will P2142 cause my car to fail an emissions test?

Yes, in most states and regions an active P2142 code will cause your vehicle to fail an OBD2-based emissions inspection. The check engine light will be illuminated, and emissions test equipment reads directly from the OBD2 port. Additionally, if you recently cleared the code, your readiness monitors may not be complete, which can also result in a test failure. Resolve the underlying fault and complete a full drive cycle before testing.

Q: Is P2142 the same as P2141 or P2143?

These codes are related but not identical. P2141 indicates a low voltage condition in the EGR throttle control circuit, while P2142 indicates a high voltage condition. P2143 typically refers to an EGR vent control circuit issue. All three point to problems within the EGR throttle control system but in different parts of the circuit. Diagnosing which wires and components correspond to each code requires a wiring diagram specific to your vehicle.

Abstract

Error code P2142 means your vehicle's Engine Control Module (ECM) has detected an abnormally high voltage signal in the exhaust gas recirculation (EGR) throttle control circuit. The EGR system recirculates a portion of exhaust gases back into the engine to reduce harmful NOx emissions and improve fuel efficiency. When this circuit reads voltage outside the normal range, the ECM triggers P2142 and may put the vehicle into a reduced power or limp mode to protect the engine.