Posts Tagged: EGR
What is an EGR valve?
What does an EGR valve do and can I delete my EGR? I often see car owners ask how to perform an EGR delete. Doing an EGR delete is a really bad idea. But in order to understand why, I first have to cover, “What is an EGR valve.” What does an EGR valve do? When the EPA first addressed air pollution, they directed their attention to the amount of unburned hydrocarbons (HC), carbon monoxide (CO), carbon dioxide (CO2), and oxides of nitrogen (NOx). By adjusting and monitoring air/fuel mixtures, … Read More
P0404 code for EGR — What it means and how to fix it
Learn what a P0404 code for EGR means and how to fix the problem A P0404 code is defined as Exhaust Gas Recirculation Circuit Range/Performance; meaning that the EGR valve is performing outside your vehicle’s parameters. More specifically, the P0404 code can mean the valve is closed when it should be open or vice-versa or that the EGR passage is restricted. It’s a generic code that indicates that the engine control module (ECM) has detected that the exhaust gas recirculation isn’t what the ECM expected to see. The EGR system … Read More
P0401 code — What it means and how to fix it
Learn what a P0401 code for EGR means and how to fix the problem A P0401 code is defined as Exhaust Gas Recirculation Flow Insufficient Detected; meaning that the commanded amount of EGR flow doesn’t match the actual EGR flow. The EGR system is responsible for diverting a certain amount of exhaust gas to the intake manifold air to reduce combustion chamber temperatures and reduce NOx formation. See this more in-depth post for more information on the EGR system and why it’s needed. The most common causes of a P0401 … Read More
P0400 code — What it means and how to fix it
Learn what a P0400 code means and how to fix it A P0400 code is defined as Exhaust Gas Recirculation Flow Malfunction; meaning that the EGR valve isn’t responding properly to the EGR flow command issued by the ECM. More specifically, it could mean the valve is closed when it should be open or vice-versa or that the EGR passage is restricted. It’s a generic code that indicates that the engine control module (ECM) has detected that the exhaust gas recirculation isn’t what the ECM expected to see. The EGR … Read More