Toyota Repair: 92 Camry Ping Sensor, salvage yard, toyota dealership

Question
I took my car to the local Toyota dealership when I noticed the check engine light on and a 50-60% loss of power. They said it was coming something triggering my ping sensor. They replaced the ping sensor and it is still doing the same thing. I believe they said the next thing on their list to replace is the ECU...should I get one from a salvage yard or do you think there is something else that might be causing it?

Answer
No, do not replace the ECU, it is last on the list of possible causes, it sounds they are just guessing what the problem may be and it's costing you money, I need to know the trouble codes(DTCs) that were in the computer that made the check engine light turn on, if I have that information I can probably help, also I need to know what engine the car has and what transmission.