I no longer have my misfire codes woo hoo! Instead I have P0136 and P0138. 136 is 02 circuit malfunction Bank1 Sensor2
138 is 02 sensor circuit high voltage bank 1 sensor 2

The previous owner had an 02 simulator installed. If this was done improperly or the box is bad could this cause these codes? I have a test pipe so I will need some type of simulator.

If it is not the 02 simulator, where do I go from there? Replace the sensors?

 

Those are both secondary O2 sensor codes so, I'd say yes, it's likely.

Bank #1 Sensor #2 is the key. It's telling you it's the secondary sensor.

 

On Friday we are going to check everything out hopefully it will be as simple as that.