Hey guys, 99 mazda b3000. i pulled a code for EGR Flow Excessive. What should i look into checking to diagnose and solve this? And is it still safe to drive?

 

The EGR (exhaust gas recirculation) system is designed to introduce a small amount of exhaust gas into the combustion chamber to keep the engine from pinging under load and hard acceleration.
It's not dangerous if the system isn't functioning properly, but it should be dealt with sooner then later.

The most common problem is the metal DPFE sensor, if you still have the metal one, replace it with the plastic one.
There are also 2 lines coming out of it that goes to the EGR chimney, replace those too.
Because you have excessive flow, your chimney is probably clear, sometimes it can get blocked up with exhaust carbon and needs cleaning.

Other thing to check is the EGR valve, make sure it isn't leaking and that the vacuum line going to it is functioning.
If you trace the vacuum line from the EGR valve, it leads to the EGR valve control solenoid motor.
The motor can fail, but a simple vacuum test will reveal that.

Here are some links as to what these things look like.

https://www.rockauto.com/en/catalog/...d+/+motor,4380

https://www.rockauto.com/en/moreinfo...447153&jsn=365

https://www.rockauto.com/en/catalog/...egr+valve,4968

https://www.rockauto.com/en/moreinfo...447153&jsn=372

https://www.rockauto.com/en/catalog/...e)+sensor,5088

https://www.rockauto.com/en/moreinfo...447153&jsn=380

https://www.rockauto.com/en/moreinfo...447153&jsn=385