The bolt on my carsound cat that goes into the o2 sensor bung fell off. I totally forgot what size bolt it was and i really dont want to take off the cat and bring it to the screw shop to find test fit bolts. Does anybody know off the top of the head what size bolt i need to go back into the o2 bung? My car is sounding pretty damn crappy with a leak...

 

M18 x 1.5. I hear spark plugs will fit.

 

hmm ok coo, im gonna try that