Starting a few days ago I notice that a I have a slight ticking noise coming from my engine bay when the car is idling. I was just wondering if someone could shed some light on what this might be. I do have a service engine soon light that came on about a week ago and it came up as an O2 sensor. Would this have anything to do with this ticking noise?

 

What octane gas you putting in, honestly?

 

Octane rating shouldn't matter at idle. With a load or up hill it shold knock(ping) if octane rating is low.

Check your oil level.

 

I use 93 octane ever since I bought the car. It has almost 92,000 miles on it and I bought it with 48,000 miles on it. I change the oil every 2500 - 3000 miles and it just had the 90,000 mile service done about 3,000 miles ago.