DTLT Headers missing an o2 sensor.. big deal?

I got a plug from advanced auto parts so the whole is filled fine. I was trying to get the sensor off the stock manifolds and i stripped it. So i have the drivers side hooked up and the passenget side plugged. Theses are the sensors before the cats that im talking about. Is this a big deal, it wont do any serious damage will it? Thanks!

 

you should problay get another o2 sensor. i haven't had any problems yet with just one o2 sensor. i think it will throw off one your air fuel ratio though.

 

The front sensors before the CATs measure the AFR. Your ECU will be making radical adjustments to try and compensate for the bad reading due to lack of signal. CEL should come on soon, I'd think....

 

has the check engine light turn on??