I just finished my tune-up and I got in the car today to let it run for a while, and I revved it up a little bit and black stuff started spraying on the ground as if it was running rich. It wasn't really smoking (out of the ordinary) but there was a puddle of black, oil looking liquid after about 10 minutes. My friend said that it's my spark plugs. He said they have to be bent up a little (something to do with more spark.) Does that sound like it may be the problem?