for another car and I need expert help on this one. 92 Camry, 4cyl. Had full blown tuneup, timing belt, fuel filter and pump, done 18K ago. Coming home from work last Tuesday, it drops to 3 cylinders and is jumping in and out of the 4th. Took it to the guy who does my work and this guy can fix anything. They've gone through every square in of it except the ECU. Codes were showing bad 02 sensor and still the same problem. Any ideas where to look? It's got us stumped. Car only has 230K on it and hate to get rid of it.