Well, I am not sure one would ever blow up on you lol. IF there is a carbon build up, and again I am not promoting a CC or disputing them but IF you have carbon build up you will or can lose proper air flow into the cylinder leading to decreased fuel economy and or performance, rough idle or if a chunk breaks off and is ingested possible cylinder damage. If it made it through the combustion chamber then it could in theory get stuck and damage your catalytic converter. These are all my opinions. I'm gonna have to put that disclaimer that Jacoby puts in his signature block into mine LOL.