Ordered the Rinehart 2-into-2 exhaust to replace my stock exhaust. I am trying to find out if I will need the bung reducers. The exhaust comes with 18mm ports and I am unsure of what size O2 sensors I have, 18mm or 12mm. I placed a wrench on one and it is larger than 12mm but much smaller than 18mm. Any idea what size these are? Did the 2012's come with an odd size?

Thanks in advance.

 

The 18mm and 12mm is referring to the thread size not the wrench size. I believe the 18mm O2 sesnor uses a 22mm (7/8 is real darn close) wrench and the 12mm uses a 14mm wrench.

 

Rineharts should come with both size O2 ports

 

Your stock exhaust has 12mm 02`s. 2011 has 18mm`s