Oxygen sensor replacement?
 

Ive got to get my car smogged before the end of this month and I was wondering if i should change the oxygen sensors. My car is a 95 mustang gt with 105,000 miles on it, I think the sensors have never been changed but im not sure? I took them out a few days ago to clean them and the car seems to idle a little better, but with the miles i have should I change them just to be safe? And if i change them, where can i buy some for a good price? I was gonna buy them from kragens but if anyone knows where i could get them cheaper that what be greatly appreciated. Thanks, :D

Probably not even worth it. If its working why replace it? My O2's are 10 years old at least and still going strong.