Honda Accord - clunking noise

I own a 2008 Honda Accord 4-dr, 39K miles. I haven't had the factory wheels on the car since I purchased it in 2008. I have 20 inch custom wheels on it. Recently I got two new tires installed and tires balanced and aligned. Since then, I hear a clunking noise - or something that sounds like it's slipping. It occurs when I put my foot on the gas after coming to a complete stop and it also occurs when I'm driving (no foot on the break, but the gas).

Thoughts about what could be causing the noise?