Burning Rubber

iTrader: (1)

I have a 95 LT1 and normally runs EXTREMELY rich but i just installed a wet nitrous kit on it with 75 shot pills. And now for some reason it runs lean even on the motor. The plugs are perfectly clean. Like there is no discoloration at all on the porcelin part or the ground starp or the electrode. The only part that had any color was on the edge of the threads, and it was black. It needs a tune really bad. But I was wondering why it would change from rich to lean even without the bottle.