I just swung a 99+ engine in my 97 cavz24. The knock sensor and upstream o2 sensors are both different and are not plugged in at the moment. Will these 2 sensors cause the car not to run. We have tested the ignition system and the spark is present but seems very weak. I have extra ignition parts, so I've already swapped coil packs, ICM, "plug wires" and even plugs. Fuel pump is working and fuel is being delivered, just no start. I am going to install the correct o2 and knock sensors tomorrow. any other advice would be appreciated.
Run ALL electronics from the 97 engine. The 99 engine should have the same O2 sensor. If it is not a purple one wire, you have a 00-02 engine.