dmont
Member
Did Spark Plug Change cause P0420 Code on 2007 Expy?
I recently had my spark plugs replaced on my 2007 Expedition, and shortly after that my truck displayed the engine dummy light which ended up being a P0420 code. This light was not on before the spark plug change.
I know that the spark plugs can be troublesome to replace, and the shop that performed the service mentioned they had to use some penetrating fluid (or similar to that) in order to get some of the plugs out.
The shop has had the truck a few times to attempt to alleviate the problem and has even cleaned the fuel system. They now want to consider replacing the catalytic converter.
I'm wondering what might cause this code given that the event that seemed to cause the code was that plugs were replaced. Based on my research it can be a variety of things from the fuel rail pressure, O2 sensors, and catalytic converter. Dirty oil was another possibility but I changed it.
Here is a picture of the Code Reader's display:
https://flic.kr/p/rkifox
I recently had my spark plugs replaced on my 2007 Expedition, and shortly after that my truck displayed the engine dummy light which ended up being a P0420 code. This light was not on before the spark plug change.
I know that the spark plugs can be troublesome to replace, and the shop that performed the service mentioned they had to use some penetrating fluid (or similar to that) in order to get some of the plugs out.
The shop has had the truck a few times to attempt to alleviate the problem and has even cleaned the fuel system. They now want to consider replacing the catalytic converter.
I'm wondering what might cause this code given that the event that seemed to cause the code was that plugs were replaced. Based on my research it can be a variety of things from the fuel rail pressure, O2 sensors, and catalytic converter. Dirty oil was another possibility but I changed it.
Here is a picture of the Code Reader's display:
https://flic.kr/p/rkifox
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