I just changed my plugs from Bosch platium to NGK TR55's last night and noticed that my old plugs where really white looking. Also the around the center of the plug the metal looks blueish, kind of like when you put on a nice set of headers and they turn blue after first running them.

If I'm not mistaken this is caused from too much heat correct?

I've only had these plugs in for about 20K miles. Also I'm wondering if my new Tune has anything to do with it.

Current setup; 5.3, stock intake, stock cam, 02' injectors, 02' PCM, basically stock exhaust w/ Edelbrock muffler.
Tune is setup for 93 octane and also deleted the EGR but I have not yet unhooked the EGR. That wouldn't have anything to do with it would it

 

White porcelain on the plugs is an indication of a lean air/fuel ratio. Lean ratios run hotter since there is little extra fuel to cool the chambers. As long as there are no signs of detonation, your ok. It probably is getting good gas mileage!

 

yes you are running a little lean.

 

Gas mileage stayed about the same for the city but hwy went up noticeably, but that is probably due to my correction of larger tires.

I did just notice today, I got into it WOT and swear I heard a little bit of pinging or detonation. Sound light and metallic.

 

i would get the tune adjusted again to be on the safe side

 

Could I possible be running too lean due to the EGR being turned off?
Correct me if I'm wrong but don't you get better performance running lean as long as there is no pinging?