Rick's Free Auto Repair Advice


P0404 Exhaust Gas Recirculation (EGR) Circuit Range Performance

If you have a P0404 EExhaust Gas Recirculation (EGR) Circuit Range Performance trouble code, read this to understand what it means

Engines recirculate a small amount of exhaust back into the intake manifold to reduce combustion temperatures and lower smog causing oxides of nitrogen emissions. The computer commands the EGR valve to open a certain amount and then checks to make sure it’s operating properly. One way to check is to mount a position sensor on the shaft of the EGR valve and generate a voltage value depending on how far the shaft moves. If the computer senses a problem with the sensor being out of acceptable range or a voltage that’s not right, it will set this code. That can either mean a bad position sensor, a bad EGR valve, or a wiring problem in the circuit. Don’t automatically assume it’s a bad EGR valve.

© 2012 Rick Muscoplat

Posted on by Rick Muscoplat

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