P0403 and P0406 codes on 2006 Town and Country
 

I only had the P0406 code at first and some experts on YouTube said that 99.8% chance it is the EGR valve so I replaced it. But now I have not only the P0406 but also the P0403 codes. I tested the 5V Supply, Position Sensor GND, and the Chassis GND and they all check out. I don't know how to check the Position Signal or the EGR control line. Any ideas on what is causing these codes? My only thought is that both the EGR valve that I replaced and the new one are no good but it seems kind of unlikely.

you used a cheap part

Yeah, I did. But you would think that it would work for a while - maybe not last as long as a factory replacement. BTW, I got the top off the old one and I think that the two contacts are corroded. They are not easy to get at for cleaning. I sprayed them with contact cleaner but I am not sure that is going to do it. Maybe I can get a small points file in there. Have to go buy one tho since I have't had need for one for a long time.

the connector on the car or the one on the part you got? neither should be because there is no way for water to get in there unless in the open aka used park.

Turns out that the cheap part was fine. I took the car into a Chrysler mechanic and they cleared all the codes and took the car for a 21 mile ride and came back and all the codes stayed gone. What I don't understand is why when I cleared them with my ODB-II scanner the came right back. I also tried disconnecting the battery and reconnecting it. Codes came back. Did I need to take the car for a 21 mile ride? I took it for a 10 mile ride. Codes came back. Why did it behave differently for the mechanics at the garage? Could it be a problem with my scanner?