Your SUV needs spark, fuel, and oxygen to run well. One of these things is lacking. Change spark plugs and wires, air filter, fuel filter, dump a bottle of chevron brand injector cleaner in your tank (cheap stuff first). Clean your MAF and throttle body replace Oxygen sensor (easy tasks with simple tools).
Could be a few things. The idle could be set too low. It could be starved for gas, with a gunked-up fuel filter, or starved for oxygen, with a blocked air filter. The timing might need to be adjusted. If those things are all right, then it's either in the electronic fuel injection, or bad gas.