Code P0404

P9494 is the EGR valve circuit range. This is usually caused by the sensor in the EGR valve failing so that it doesn't report the position of the pintle inside the valve to the PCM correctly. To test it requires a scan tool to read the sensor while commanding the EGR valve to open and close. Without the scan tool to test the EGR the next option is changing the EGR valve, because the normal cause is that the pintle itself corrodes so that it binds and cannot move easily so the sensor doesn't move either. The hard part of changing it is usually that the bolts securing it corrode as well and cause problems.

Hello Steve W., the code was P0404. Is the information you sent me for code P9494 the same for my code P0404? Thanks, Jim

OOPs sorry that was supposed to be code P0404 Fat fingers on my part hitting the 9 instead of 0. All the info applies. Sorry again.