Since you added injector cleaner, and the engine started behaving like you described, I would test the injectors.
If you have a DVM (Digital Volt Meter) you can do a simple test.
Cold engine, open the hood, remove the connector to the first injector (press the metal clip and pull the connector).
Now, set the DVM at 2K or 200 ohm and put the leads on the injector and write down what you get.
Then you put the connector back on and proceed with the other ones, so you won´t mix up the connectors and injectors.
Do so with all 8.
They should show values between 12 and 17, but they can´t differ more than 0.3-0.5 ohm from each other.
If there is one that is like under 10 ohm, you found a very possible cause to the erratic idle and gas in the oil smell.
You can perform this on a warm engine as well.
Check this one out in case of injector failure, you could call him the king of injectors.
Fuel Injector Connection
Or look on the left side of this page for SouthBay Fuel Injectors, same products.