Egr valve needs replacing

It has an expansion valve, not an orifice tube. It is in the evaporator case.

Integra stalls because you need a tune-up. And have the timing checked. I bet you need a new distributor too. And have the ECM (car computer) checked as well.

Depending on where its located, and if you can get to it easily, its pretty simple. Just remove the bolts holding it in place, and unplug the connector. Might have a gasket between egr valve and mounting surface, remove old one and replace with new gasket, then put new egr on reverse of removal.

Check this website, you should find this information there.

Acura Integra 1991 1993 wiring diagrams fuse block

On this website, you find fuse box diagram and description for Acura Integra (1991 - 1993)

Acura Integra 1991 1993 wiring diagrams fuse block

Standing by the passengers fender it is mid way down the engine and is bolted to the transmission.Follow the cable from the positive post of the battery and it will end up at the positive post of the starter solenoid switch.

It sould be as easy as a fuse or most likely you will need to have the switch replaced

In the gas tank.

P1399- Acura = Random/Multiple Cylinder Misfire Detected

Acura forums state that It could be a coil pack or O2 sensor, or EGR.

In my experience by far Ebay Motors is your best source for a specific model like this.