So I installed my o2 simulator, hoping my codes or any future codes would go away and disappear. It was fine for 40 miles after I left my battery unplugged but then it popped back up with a vengence. I have P0139 and P0159, both are o2 sensor slow response for both rear sensors, and P0158 and P0138, high voltage for both rear sensors. I was pretty sure that the o2 sim was suppose to supress any o2 codes for the rears. I connected the sim wires properly, via BlackbirdVQ's write up in the how to's.

I also came up on two other codes:
P0505 Idle system (correctable by the learning procedure in the how to's)
P1320 Misfire (for ignition coils)

I am pretty sure these two wouldn't have anything to do with the o2 sensor, right? As of this point, I am ready to remove the o2 sensor, wait for the light to come on again, and get the check engine light rechecked to see if the o2's are setting off any codes again. But like I said, why would the o2 sim set off the o2 codes mentioned above?

Thanks for your help

BTW, I have a y-pipe and intake.

 

I assume you have a dual output sim for 2 sensors, instead of connecting it the way BlackBirdVQ described, try connecting it the way that it is described in the installation instructions for the simulator. Another thing to keep in mind is that the simulator may be defective (happened to me). To test it, connect the red wire to battery 12V terminal and black to GND, measuring with a meter (I used a scope) the signal should be switching between 0V and 1V every few seconds...

P0505, you may need a new IACV, and P13XX are your coils. O2 sensors may have gone haywire because of the mulfunctioning coils and messed up air...

 

P0158 and P0138 probably means your o2 sim is defective, which I had in my case also.

Take a multimeter and check for the oscillating voltage in the white output wire on the o2 sim. It should be from 0 to at LEAST 0.6V on every oscillation. The ECU looks for a voltage range of 0.6V-1.0V for the secondary o2 sensors when the vehicle is running. It throws those two codes when that doesn't happen