I have a 2013 Acura RDX it what are some good mods for performance any ecu tunes, or cold air intakes, or is it good to do the muffler delete?

 

Aftermarket "cold air" intakes will just pull in hot air. A drop in air filter from K&N that goes in the factory airbox might give you a tiny boost in performance, but don't use it if you drive in very sandy/dusty areas. A muffler delete wouldn't make sense for this car. You may be able to have an ecu tune done, but I'm not familiar with them on these cars. Your best bet it to always use 91+ octane and keep up with maintenance.