Couple days ago noticed my car has a backfire when coming to a stop after driving. During driving, no issues at all. Come to a stop sign, and have like one backfire. Have started car and let it sit and idle for while and nothing. Should I be looking at wires and plugs first??

 

Do you have a SES light on?

 

Yes, have an o2 sensor that is running slow. It registers a reading, but slower then other side.

 

Check for a exhaust leak first. It will cause a backfire on deceleration and depending on where the leak is could cause your O2 to read incorrect.