I only cleaned one of the ports so you could see the difference, I'm new to this so I was just wondering if this was normal? Also I never expected it to be so easy to clean all I did was wipe it with a dry paper towel and that was the result. Also it looks like I may have some rust spots forming on my exhaust, I thought these things were stainless steel?

 

when my o2 sensor was going bad and my car started running rich the same thing happened to my exhaust...could be the case for you too

 

It's been like this for a few months but since then I've added intake and headers so we'll see what happens. I can't remember whether or not I had reset my ecu before these got all black. I didn't reset my ecu for a few days after the install so that could've caused it. Or this could've been caused by the Seafoam treatment I did after installing these. Now that I think about it, if this isn't normal than it was probably the seafoam that caused this.