Grab a throttle position sensor and mass airflow sensor off amazon. Think they run around $70 shipped for both of them. I had the same exact problem with mine. It was the throttle position sensor. Grabbed the mass airflow sensor while I was at it because it was so cheap. When I pulled that out, I could tell it was a good idea to replace it, as it was all gunned up.
Fired her up after that and she's been golden ever since.
Easy fix and one you should be able to do yourself too! Think you just need a torx bit to take the screws out...
