Acts like it isn't geting gas on 2004 Nissan Murano

There are times when I am driving and my car acts like it isn't getting gas. i can push the gas pedal all the way down and nothing. then do it again and it takes off. also, when driving is acts hesitant.

Asked by for the 2004 Nissan Murano
have the fuel pressure checked. have the cat converter back pressure cheked.

Sometimes the engine light comes on but then goes back out after i add fuel injector cleaner. Will the cat converter cause this type of problem? Is there a front and rear catalytic converter? if so, which one need to be replaced - rear? Thanks so much for the help.