My car does pretty much the same thing...When I shift into any gear it always jumps like i'm not giving it enough gas. So, it could be my spark plugs or my injectors need to be cleaned?

I know my fuel lines were dirty and the shop I had it in cleaned it out/fixed it, but I'll run a gas treatment/injector cleaner through it and let you guys know how that went...after that, should I look into changing the spark plugs? How can I look at them and tell they're bad?