Ford 2003 Expedition 5.4 Eddie Bauer
P0405 code was found on my own scanner and Autozone.
This code was supposedly fixed by an mechanic, it came back on car was taken back to the mechanic.
Now he is saying to change the catalytic converter, there were no codes for that!
whats the steps moving forward?
i am not into fixing things that are not broken.
I would definitely replace the EGR valve before even thinking about catalytic converters. I have 1999 Ranger with almost 300k miles on it, and it's on the original cats.
P0420 is a code that might signal the catalytic converter is no longer efficient. It's not a surefire thing, even then. If you had that code, it's no guarantee that the converter is bad. It's all based on oxygen sensors, there's one on either side of the converter to gauge the catalyst's efficiency. If there's an exhaust manifold leak, it may trip the inefficient catalytic converter code, even though it's actually fine.
This is why troubleshooting is so critical. That "mechanic" is a parts changer.
Now he is saying to change the catalytic converter, there were no codes for that!
There are no codes that definitively say a specific part has failed. Codes indicate a condition exists which usually can have multiple possible causes. Have the potential causes of P0405 been looked into?
https://www.obd-codes.com/p0405
