CEL came on today and it was a P0400 code. Is the car picky in terms of OEM EGR or aftermarket Valve? Is there any other common culprit? Car appears to run fine! Any help is greatly appreciated!

Thanks Martin

 

I replaced mine recently with one off of Ebay for $30 and haven't had any issues. It turns out they are the same EGR valves used on the GM 3800 V6 engines from the late 90's/early 2000's.Sometimes you just might need to clean the port out below the valve from any carbon buildup.