I may be right but i want to double check. Im throwing codes on my mustang and the check engine light is on. I need to do emmisions and guess im going to replace my o2 sensors tonight and see what happens. im a dork and dont have the codes with me but the code was an issue with the upflow... Is that o2 sensor? im not sure i will post later with the codes.

 

NO IDEA what you're talking about. Do yourself a favor and don't start throwing parts at it until you know what you're after.

 

Thats the best troubleshooting advice anyone can give.

o2 sensors are a lot of money especially if you buy OEM.