ck76239

This is going to sound weird, but my new cat converter humms. I fired up my new engine yesterday, and ran it for 25 minutes at 2000-2500 rpm, then I shut it down. When I shut it down, I was hearing a funny niose, kinda like a electrical fuel pump. Well I dont have an electrical pump anymore, I removed it from the tank.

So I turned off the lights in the garage thinking it was a ballast on one of the flourecent lights. Then I disconnected the battery, and still heard the noise.

So i walked around the car and found it was coming from my Cat Converter. Its a brand new Catco brand converter, universal application w/ no provision for air injection since my air injection system is long gone. The car did not have a cat on it before, but I thought I'd try to do my part for the enviroment and put one on...

Any ideas why this thing is making noise? It continued the noise for maybe 1/2 hour or so until it cooled.... I'm having a little trouble with my timing, it's a little advanced, I can't see how that would have any effect on the cat, if it was retarded yes, but not advanced????