yo whats up i have a 92 honda civic EX that has a D15z1 swap in it that my buddy put it. But i have a lot of questions about how the how the whole EGR system works? I have a lifter valve on it but doesnt have any vacum lines going to it? And on the intake manifold toward the fire wall has an extra SOMETHING? I am not sure what it gos to but maybe like a vacum line gos to it? And why does the harness have an extra plug on the strut tower? I have an cell light on in my car and its for the 02 sensor but i replaced it and trouble shooted everything and have no idea. So anyhelp would be cool and some wiring diagrams for the engine harness casue i am not sure but i think some one was messing around with it and the ECU.

 

I have a P07 ECU in it but the wires going to it look like they were spiced in to.