My oxygen sensor was new about a month and a half ago.

When the dealership ran injector cleaner through my car, they forgot to disconnect the fuel pump. I noticed something running out of my tailpipe and I'm guessing it was fuel.

Now when the vehicle is cold it doesn't seem to idle as high. I have also had the rpms drop below 500 when sitting in traffic shortly after startup.

I don't have a check engine light, but was just wondering what you thought.

Thanks