I popped the hood today and heard a strange noise. It appears to be coming from my smog pump. I relocated it down by the old air filter location when i did the SC install. It sounds like a humming sound that would be like a radio being between stations and making a steady sound. I have been looking for exhaust leaks for months and found them all so this engine was as quiet as ever. This noise can be heard over all other noises and has me stumped. Im am dead certain it didn't make this noise ever before or at least could be heard over the engine.

 

Unplug it and see if the noise goes away.

Rich