99 Yukon slt 4x4, whats this plug/harness for?

[knoslf]

Hello guys does anyone know what this plug is for? its coming from a harness in front of the pcm(not attached to the pcm), not sure where the harness goes to, but theres also what appears to be a ground wire as well, neither are being used, just hanging there. The plug has a little blue plastic tie like on it and the ground has plastic loom around it...heres the pics does any of this look familiar? My truck has been cutting off a few times lately when it very hot out here(in Denver) and I happen to notice this, im assuming I need them sine they came with the car??

 

[SunlitComet]

electric A.I.R. emissions pump perhaps.

 

[knoslf]

electric A.I.R. emissions pump perhaps.

Thanks, but what is the 'electric A.I.R. ' and where is it located? Is it sacrificing the performance of my truck?

 

[SunlitComet]

rectangular device in bottom left of Picture #2.