I was trying to take apart my motor today. I tried to get the header off but there is a fitting on it. a tube that goes back to all the vacuum hoses at the back of the motor. If i dont plan on using EGR anymore anyway, can I just plug the fitting and the one to the EGR stuff? I'm getting a DC header.

 

sure

 

i think it will throw a code.

 

now that i think about it, yeah youre right. unless you flash your ecu

 

Disabling EGR without a reprogrammed ECU can also lead to part-throttle knock.

 

But the code wont slow it down right? I've got an safc ready to go in.

 

It will slow it down, ( it actually retards timing and increases fuel as a safe mode). Fuel richness in lower RPMS can choke the engine a bit.
ECCS On Board Diagnostics increases fuel richness when ever part of the emissions system fails (only for California models, which make up 2/3 of the U.S Market). Basically it is just a waste of fuel and power if you aren't running stoich, or somewhat lean.
Safc would lean it out in the lower RPM's and posibbly you can tune it in the higher RPMs as well to pick up a little more power. I wouldn't do this unless you were dyno tuning it though, you might blow your engine.