2017-10-10
Illuminated check engine light
Reduced engine power or acceleration
Decreased fuel efficiency
Rough idle or stalling
Smoke from the exhaust system.
Failed exhaust pressure control valve
Faulty wiring or connections in the circuit
Loose or corroded electrical connections
Failed engine control module (ECM)
Exhaust Back Pressure Sensor: Exhaust Back Pressure sensor detects any kind of back pressure in the exhaust system. Back pressure is the pressure opposite to the exhaust flow resulting in a lower power output. This car's malfunctioning back pressure sensor may lead to higher emissions & lower performance
Replace the exhaust pressure control valve
Check and repair any damaged wiring or connections
Tighten or clean any loose or corroded electrical connections
Replace the engine control module (ECM) if necessary
See which problems come with P0478, how often it shows up in other vehicles, and how to fix it — step by step. Free on OBD DashX, in 10 languages.
See P0478 on OBD DashX