how many miles do you got on ur Z syf0n? My car is also running rich w/ a lot of breathing mods I've done. I can sput out black smoke that you could light on fire if you had a lighter out the window and some luck. But I'm also at altitude so I'm not sure exactly how much richer it makes the car, but I'd say noticeably. I also say I'm running rich because the car is a gas HOG.

 

I have 40,000 miles on my car. I am only a hundred or so feet above sea level, if that...FWW my car does actually shoot fire from time to time :P



It started happening a few months ago after I put the Nismo exhaust on...

 

The color of the ceramic by the electrode is the temp indicator reading area on the plugs, and they look white lean to me, the rest of the color is of no account.