You won't have to do an oil change right after the seafoam you can buy it at NAPA . Pour in 1/2 a can and drive it like you stole it. No need to drain the oil after, it will evaporate through the EGR valve, the other 1/2 can goes in the gas tank that's 1/4 full. It will clean out the fuel system as well. Read the can. I use it about every 2 months and only change the oil at 6000 miles, with synthetic, I change oil at 10000 mikes. Though I DON'T recommend it, my friend had his first oil change on his Toyota Corolla SR5 at 48000 miles.