My computer is pulling this code, I think is has something to do with emissions, can anyone help with this. thanks

 

P0420 Three Way Catalytic Converter (TWC) system low efficiency Bank 1

Basically telling you that the PCM thinks the LH cat is not working well, based on info received from the post cat sensor on that side. Could be the cat or maybe even the sensor is giving false indications.

 

I have an 02 sensor off of my obd1 car, can I throw that sensor on there and see if that is the problem, are the sensor for obd1 and 2 the same.
thanks

 

No, the connector for the rear O2s is square. Your OBD-I sensor and the front OBD-II sensor (same) have flat connectors. Try swapping your rear O2 sensors and see if the trouble follows the sensor.

 

thanks shoebox, I will switch those and repost with results