Hello, I have the Greddy SP2 Cat back. I have an extra o2 sensor hole in it right near the main cat. What size thread is that? I have a 3/8" pipe fitting plug in there right now, but I think I could find a better fit. So what size are the treads, what did you guys use, and where can I get a bolt for it? Thanks...

Aaron

 

M18x1.5...u can probably find a bolt at ur local auto shop.

 

Thank you! I'll check around here now that I know the size.