I changed my O2 sensor but now there is a popping sound that comes when you first start rolling out of first. It almost sounds like some kind of electrical discharge. It's not very loud but it's there.

Any ideas what this might be?

I noticed immediately that the O2 sensor was good. I have no hesitation nor power surges anymore...

 

Is it coming from the exhaust? You might be running slightly rich.

 

if you didn't use the OEM o2s, pls double check and make sure you have the wiring setup correctly. My old Legend cooked its cat b/c of it.

 

The replacement piece I got was from The parts bin - they rock by the way. Got the piece MUCH cheaper than from any other place that I could find.

The piece is exactly the same as the one that I replaced. The plug at the end can only fit one way so I don't think I can even get it to go on the wrong way.

It's not a loud pop, more like a slight discharge. It doesn't sound like a backfire or excess gas burning off.

I'm going to take a look under the car again today and see if I can figure it out...

Pretty strange...