things you can try before paying..

cleaning the throttle body yourself, they get gummed up. could be the surging idle, but not the exhaust smell.

check egr actuator for leaks, it will suck in most likely, mist it with starting fluid and see if it raises rpm (do this ONLY on the intake side, not exhaust)

mist the coil pack and wires with water.

check spark plugs.

thats about 30-40 minutes of work to eliminate a bunch if potential issues.