OK I have been running NGK 2023 BPR7ES spark plugs in my car for some time. The first time I changed them after 3000 miles and they looked brand new. I had them gapped to .026 - My Car has been running kinda weird lately, so I checked the plugs and they were all black with a reddish tint only after 1000 miles this time. What could cause this? Too big or small of a gap perhaps? I put new plugs in gapped to about .025 this time, and the car runs like I remember it. I have not changed anything with my car that would affect my tune. One more thing, I notice a lot of black soot on the garage floor behind my exhaust pipe from letting my car idle, is this bad?

 

Black and Soot = rich. So it's running abnormally rich for some reason. Could be a vacuum/boost leak, bad O2 sensor, screwed up MAF....

 

at idle my A/F is about 14.7 - 15.0 and at WOT its in the 11's