when I shift into reverse, the idol drops and the engine stalls. Any thoughts? on 2000 Nissan Altima

All new sensors {cam, crank & air mass }. New dist., plugs & wires. Also new tps control mod. It did this once before and I found that when the oil was serviced that they had changed the air filter & never re-tightened the clamps on the air supply hose. {Trick of the trade move to get you to come back} Not the case this time

Asked by for the 2000 Nissan Altima