My check engine light came on so I had it tested at autozone. The guy said it was my EGR valve, so i replaced that and reset the computer. Sure enough the light came back on reading the same thing. I am not sure what the code exactly is and i only know basic mechanics, but does anyone know if your oxygen sensor could set that off and have it read as my egr valve. Thanks

 

The code number and what system tester it's for would help. Electrical flow is even a mystery to good mechanics so don't feel out of place. Basically if a part or wire grounds out due to overload an electrical signal could result anywhere elsewhere. Thereby is the immense downfall of computerized auto/truck systems. Yes - two results can be portrayed on the same trouble code. Even more than that with certain testers (which makes diagnosis a real b**ch). A very alert mechanic who is good with electrical systems and has a good tester might make quick work of it?

 

EGR on Ford is so stupid it fails all the time. there is also a sensor called DPFE that can fail too. and there is a small vacum pump that operates the EGR that can fail. and then the EGR ports in head can get cloged so that can cause problems too. what engine do you have? I have a 01 with 4.2L engine and I replaced just about everything.

 

I have a v8 5.4L. Found something else interesting, when i kick my tail pipe, "knocking snow off" my check engine light will go off for maybe a day. Could an o2 sensor be causing my check engine light. I'm pretty sure there is a sensor not far from the tail pipe an two more head up towards the fround an possibly a fourth haven't tried to replace the sensor to damn cold out right now. Any ideas?