Running Rich
Running Rich 
if you plan on getting a tune dnt bother with the 02 simms you can delte the 02 in the tune.... i ran 02 simms on the rear 02's for about 6 months and had no problems at all..now they are taking up space in the tool chest.
Only the front O2's mean anything for fueling purposes and you can't simulate those. The rears are just to make sure the cats aren't dead. If you're running rich, you'll need to fix that with tuning software. Unless, you have some defective parts. When troubleshooting, I'd start with checking the things you've changed. Make sure you have no exhaust leaks as they will fool the front O2's into thinking you're lean. Then, go with a basic refresh by changing the fuel filter, spark plugs, wires (if needed), and O2 sensors up front. It'll set you back a couple hundred, but it's the kind of maintenance that people forget to do once they've changed the oil and refilled the washer fluid. If it's still running rich after all of that, I'd check into cleaning or possibly replacing your MAF sensor. It can be cleaned, but you need to take extreme care while doing so as the little wires are very sensitive. If you still have no luck...then tuning software is the only other thing that can help you.
