I used an intake cleaner to help reduce my smoke. The throttle body and intake soot and carbon up. It should be done with regular maintenance to clean throttle plate and bore as well as keep intake runner clean. Cleaner= less build up= more smoother air flow= more power and better mpg. I strictly use a professionally obtained clean from bgproducts.com (I get it through work) it easily removes built up and I also run the engine and inject into intake tube vent hose to clean further and get runners, valves and comb. chamber. The crap that will make it out of the exhaust will surprise you when using quality product.